Deckert J, Catalano M, Syagailo YV, Bosi M, Okladnova O, Di Bella D, Nothen MM, Maffei P, Franke P, Fritze J, Maier W, Propping P, Beckmann H, Bellodi L, Lesch KP.
Excess of high activity monoamine oxidase A gene promoter alleles in female patients with panic disorder.
Hum Mol Genet 1999 Apr;8(4):621-4
"A genetic contribution to the pathogenesis of panic disorder has been demonstrated by clinical genetic studies. Molecular genetic studies have focused on candidate genes suggested by the molecular mechanisms implied in the action of drugs utilized for therapy or in challenge tests. One class of drugs effective in the treatment of panic disorder is represented by monoamine oxidase A inhibitors. Therefore, the monoamine oxidase A gene on chromosome X is a prime candidate gene. In the present study we investigated a novel repeat polymorphism in the promoter of the monoamine oxidase A gene for association with panic disorder in two independent samples (German sample, n = 80; Italian sample, n = 129). Two alleles (3 and 4 repeats) were most common and constituted >97% of the observed alleles. Functional characterization in a luciferase assay demonstrated that the longer alleles (3a, 4 and 5) were more active than allele 3. Among females of both the German and the Italian samples of panic disorder patients (combined, n = 209) the longer alleles (3a, 4 and 5) were significantly more frequent than among females of the corresponding control samples (combined, n = 190, chi2 = 10.27, df = 1, P = 0.001). Together with the observation that inhibition of monoamine oxidase A is clinically effective in the treatment of panic disorder these findings suggest that increased monoamine oxidase A activity is a risk factor for panic disorder in female patients." [Abstract]

Sand P, Lesch KP, Catalano M, Bosi M, Syagailo YV, Okladnova O, Di Bella D, Maffei P, Heils A, Friess F, Politi E, Nothen MM, Franke P, Stober G, Fritze J, Maier W, Propping P, Beckmann H, Bellodi L, Riederer P, Deckert J.
Polymorphic MAO-A and 5-HT-transporter genes: analysis of interactions in panic disorder.
World J Biol Psychiatry 2000 Jul;1(3):147-50
"Recurrent panic attacks, anticipatory anxiety and phobic avoidance characterise panic disorder. The influence of genetic factors on liability to the disease has been the object of several linkage and association studies and appears to relate to an oligo- or polygenic rather than a monogenic mode of inheritance. Recently, an excess of high activity monoamine oxidase A (MAO-A) gene promoter alleles was found in female patients with panic disorder. An analysis of possible synergistic effects of the MAO-A gene promoter variant and the short serotonin transporter (5-HTT) gene promoter variant in panic disorder was performed in a German and an Italian sample (combined panic disorder n = 144, combined controls n = 175). There was no significant difference in odds ratios, suggesting that the observed increase of genetic liability by the long MAO-A gene promoter allele is not modified by the 5-HTT gene promoter polymorphism." [Abstract]

Tadic A, Rujescu D, Szegedi A, Giegling I, Singer P, Moller HJ, Dahmen N.
Association of a MAOA gene variant with generalized anxiety disorder, but not with panic disorder or major depression.
Am J Med Genet 2003 Feb 15;117B(1):1-6
"This study was conducted to detect a possible association of a T941G single nucleotide polymorphism (SNP) in the monoamine oxidase A (MAOA) gene with generalized anxiety disorder (GAD), panic disorder (PD), or major depression (MD). Fifty GAD patients (34 females and 16 males), 38 PD patients (21 females and 17 males), and 108 MD patients (80 females and 28 males) were included. The comparison group consisted of 276 (132 females and 144 males) unrelated healthy individuals. The 941T allele was over-represented in patients suffering from GAD (chi(2) = 6.757; df = 1; P < 0.01, not corrected for multiple testing) when compared to healthy volunteers. No association was observed in MD or PD. This is the first study specifically analyzing the MAOA G941T polymorphism in GAD and thus needs to be replicated in an independent sample. However, the results are in line with previous data suggesting an association between the MAOA locus and regulation of complex human behavior." [Abstract]

Maron E, Tasa G, Tõru I, Lang A, Vasar V, Shlik J
Association between serotonin-related genetic polymorphisms and CCK-4-induced panic attacks with or without 5-hydroxytryptophan pretreatment in healthy volunteers.
World J Biol Psychiatry. 2004 Jul;5(3):149-54.
Genetic regulation of the function of serotonin (5-HT) may be important for the neurobiology of panic disorder. In order to evaluate the influence of 5-HT-related gene variants on the vulnerability to panic attacks, we genotyped 32 healthy volunteers who participated in the study of the effect of 5-hydroxytryptophan on panic attacks induced with cholecystokinin tetrapeptide (CCK-4). The polymorphisms of interest included those of 5-HT transporter (5-HTTLPR) and monoamine oxidase A (MAO-A promoter region) genes. The results showed significant associations between certain genotypes and panic rate in females but not in male volunteers. Specifically, there was a significantly lower rate of CCK-4-induced panic attacks in female subjects who had MAO-A longer alleles or 5-HTTLPR short allele gene variants. These data suggest that functional genetic polymorphisms of the 5-HT system may influence the vulnerability to panic attacks and add to the growing evidence of inhibitory function of 5-HT in the neuronal circuitry of panic. [Abstract]

Gelernter J, Bonvicini K, Page G, Woods SW, Goddard AW, Kruger S, Pauls DL, Goodson S.
Linkage genome scan for loci predisposing to panic disorder or agoraphobia.
Am J Med Genet 2001 Aug 8;105(6):548-57
"We conducted a 10 cM linkage genome scan in a set of 20 American pedigrees (153 subjects), ascertained through probands with panic disorder (PD). Several anxiety disorders segregate in these families; they were diagnosed on the basis of Schedule for Affective Disorders and Schizophrenia interview. In this article, we describe results for panic disorder and agoraphobia, which are closely related, common, heritable anxiety disorders. This is the first complete linkage genome scan for agoraphobia and the third for PD. A total of 407 markers (389 autosomal, 18 X chromosome) were genotyped. Multipoint LOD score and NPL analysis were completed using GENEHUNTER2. For PD, two genomic regions meet criteria for suggestive linkage. One of these regions is on chromosome 1 (LOD score = 2.04). This region coincides with a region that generated a LOD score of 1.1 in a previous genome scan by Crowe et al. [2001: Am J Med Genet (Neuropsychiatr Genet) 105:105-109]. The other (LOD score = 2.01) is located on chromosome 11p and occurs at marker CCKBR, one of eight candidate genes examined. For agoraphobia, the most promising potential linkage was on chromosome 3 (NPL score = 2.75; P = 0.005). This was accounted for primarily by a single family that by itself generated an NPL score of 10.01 (P = 0.0039) and a LOD score of 2.10. These results provide initial evidence for a genetic locus on chromosome 3 that contributes to risk for agoraphobia. They also support suggestive linkage to two risk loci for panic disorder. Additional potential loci were identified with lesser statistical support; several of these were consistent with previously reported panic disorder linkage results. Overall, the results presented here suggest that PD and agoraphobia are complex traits that share some, but not all, of their susceptibility loci." [Abstract]

Ebihara M, Ohba H, Hattori E, Yamada K, Yoshikawa T.
Transcriptional activities of cholecystokinin promoter haplotypes and their relevance to panic disorder susceptibility.
Am J Med Genet 2003 Apr 1;118B(1):32-5
"We previously identified a polymorphic compound short tandem repeat (STR) in the 5'-regulatory region of the cholecystokinin (CCK) gene, and showed that when the STRs were classified into three groups based on length and linkage disequilibrium behavior with neighboring variants, the medium class allele was significantly associated with panic disorder. The present study examined the transcriptional activity of the CCK promoter construct containing the STR and downstream -188A/G variation. The STRs acted as transcriptional repressors with a similar potency among the three classes, but the long (L) class STR exhibited a synergistic effect on decreasing promoter activity when combined with -188G. The haplotype composed of the L class of STR and -188G was significantly less frequent in panic disorder (P = 0.0032; odds ratio, 95% confidence interval = 0.06, 0.01-0.69). These results suggest that the L-(-188G) haplotype may act as a protective factor against panic by reducing the expression of anxiogenic CCK." [Abstract]

Hattori E, Ebihara M, Yamada K, Ohba H, Shibuya H, Yoshikawa T.
Identification of a compound short tandem repeat stretch in the 5'-upstream region of the cholecystokinin gene, and its association with panic disorder but not with schizophrenia.
Mol Psychiatry 2001 Jul;6(4):465-70
"The cholecystokinin gene (CCK) is thought to play a role in the pathogenesis of both panic disorder and schizophrenia. In this study, we have extended the 5'-upstream sequence of the CCK gene, and identified a compound short tandem repeat (STR), located approximately -2.2 to -1.8 kb from the cap site. This STR was found to be polymorphic with ten different allele lengths. Case-control studies using 73 panic patients, 305 schizophrenics and 252 controls showed a significant allelic association with panic disorder (P = 0.025), but not with schizophrenia. Dividing the STR alleles into three classes according to length, Long (L), Medium (M) and Short (S), produced strong genotypic (MM) (nominal P = 0.0014) and allelic (M) (nominal P = 0.0079) associations with panic disorder. screening the newly extended promoter region detected not only the previously identified -36c>t and -188a>g single nucleotide polymorphisms (SNPs) but a new rare snp, -345g>C. Neither of the former two SNPs showed significant association with either panic disorder or schizophrenia. Haplotypic distributions of the STR and SNPs -188 and -36 were significantly different between panic samples and controls (P = 0.0003). These findings suggest that the novel STR or a nearby variant may confer susceptibility to the development of panic disorder." [Abstract]

Kennedy JL, Bradwejn J, Koszycki D, King N, Crowe R, Vincent J, Fourie O.
Investigation of cholecystokinin system genes in panic disorder.
Mol Psychiatry 1999 May;4(3):284-5
"There is evidence for the role of the cholecystokinin (CCK) neurotransmitter system in the neurobiology of panic disorder (PD). The CCK receptor agonist, CCK-tetrapeptide (CCK-4) fulfills criteria for a panicogenic agent and there is evidence that PD might be associated with an abnormal function of the CCK system. For example, PD patients show an enhanced sensitivity to CCK-4, and exhibit lower CSF and lymphocyte CCK concentration as compared to healthy controls (reviewed by Bradwejn et al.). Also, untreated PD patients display an increased CCK-4-induced intracellular Ca2+ mobilization in T cells relative to treated PD, depression and schizophrenia. The CCK receptors have been classified into two subtypes: CCK-A and CCK-B. We report here a study of polymorphisms in the CCK pre-pro hormone gene (CCK), CCK-AR, and CCK-BR in DSM-IV panic patients (n = 99) vs controls matched for gender and ethnicity. The CCK polymorphism revealed no association with PD. We identified a new polymorphism for the CCK-A receptor gene, and tested it in our sample, with negative results. A single nucleotide polymorphism has been found in the coding region of the CCK-B receptor gene (CCK-BR) and D Collier (personal communication) identified a highly polymorphic dinucleotide (CT)n microsatellite in the 5' regulatory region. For the CCK-B receptor gene polymorphism, PD patients showed a significant association. Our genetic dissection of the CCK system thus far suggests that the CCK-B receptor gene variation may contribute to the neurobiology of panic disorder." [Abstract]

Miyasaka K, Yoshida Y, Matsushita S, Higuchi S, Shirakawa O, Shimokata H, Funakoshi A
Association of cholecystokinin-A receptor gene polymorphisms and panic disorder in Japanese.
Am J Med Genet B Neuropsychiatr Genet. 2004 May 15;127(1):78-80.
Several lines of evidence have suggested that naturally occurring alterations in cholecystokinin (CCK) systems could contribute to the development of panic disorder (PD). Among recent investigations, polymorphisms of the CCK and CCK-B receptor (R) genes were investigated, but the results were inconclusive. We recently cloned the genomic structures of human CCK-AR, and determined the transcriptional start site of the human CCK-AR gene. Two sequence changes were detected in the promoter region: a G to T change in nucleotide -128 and an A to G change in nucleotide -81 (GenBank database under accession number D85606). The frequencies of the genotypes and haplotypes of these two polymorphisms were compared in 109 Japanese patients with PD and 400 age- and gender-matched normal Japanese control subjects. The frequency of variant genotypes (-81A/G, -128G/T; G/G, G/T, and G/G, T/T) having variant haplotype (-81G/-128T) was significantly higher in PD than in controls (P < 0.0001, OR = 2.81, 95% CI = 1.74-4.39). The statistical differences between the haplotype distributions in the PD and control groups were highly significant: the frequency of variant haplotype (-81G/-128T) was higher in the former group than in the latter (P < 0.0001). This association was not affected by clinical characteristics such as age, gender, and age at onset of PD. In this study, the first to report the positive association of the CCK-AR polymorphisms and PD, haplotype analyses further strengthened the association based on our comparison of genotype distributions. The CCK-AR gene polymorphism may be involved in the neurobiology of PD. [Abstract]

Wang Z, Valdes J, Noyes R, Zoega T, Crowe RR.
Possible association of a cholecystokinin promotor polymorphism (CCK-36CT) with panic disorder.
Am J Med Genet 1998 May 8;81(3):228-34
"We searched for mutations in the CCK gene in panic disorder with single-strand conformational polymorphism (SSCP) analysis of the three exons and promotor region of the gene. We found a C-->T transition at position -36 (CCK(-36C-->T)) in a GC box, a binding site for transcription factor Sp1, in the promotor region. The allele frequency was 0.168 (95% CI, 0.116-0.221) in 98 persons with panic disorder and 0.083 (95% CI, 0.059-0.107) in 247 geographically matched, unscreened controls. A transmission disequilibrium test based on panic disorder as the affected phenotype was nonsignificant (chi2 = 0.93), but when panic disorder or attacks were considered as affected, statistically significant transmission disequilibrium was detected (chi2 = 4.00, P < 0.05). Linkage analysis was uninformative. In exploratory analyses to search for clinical correlations, the "T" allele was found in 59% of 22 persons with panic attacks but not panic disorder, compared with 31% of those who met the criteria for panic disorder. An association between the CCK polymorphism and panic disorder cannot be considered established due to the inconsistencies in the results noted above, but if the provisional association can be replicated, the findings are consistent with CCK(-36C-->T) being a disease-susceptibility allele that alone is neither necessary nor sufficient to cause panic disorder but that increases vulnerability by acting epistatically." [Abstract]

Hattori E, Yamada K, Toyota T, Yoshitsugu K, Toru M, Shibuya H, Yoshikawa T.
Association studies of the CT repeat polymorphism in the 5' upstream region of the cholecystokinin B receptor gene with panic disorder and schizophrenia in Japanese subjects.
Am J Med Genet 2001 Dec 8;105(8):779-82
"The tetrapeptide of cholecystokinin (CCK), CCK-4, is known to induce panic attacks in human subjects, while CCK-8 is reported to have a therapeutic effect on schizophrenia symptoms. Recently, we have identified a novel microsatellite polymorphism in the 5' upstream region of the CCK gene and shown a significant association between this polymorphism and panic disorder. In this study, we have investigated the CCK-B receptor (CCKBR) gene, which is the main constituent of the CCK receptor in the CNS. Recently, a dinucleotide repeat, (CT)(n), in the 5' regulatory region of the CCKBR gene was reported to be associated with panic disorder in Canadian samples. To evaluate an association of the CT repeat with panic disorder and schizophrenia, we genotyped 71 subjects with panic disorder, 154 schizophrenics and 199 controls. However, no evidence of allelic association was found between the polymorphic repeat of the CCKBR gene and either panic disorder or schizophrenia (P = 0.186 and 0.987, respectively). Together with the negative reports on association analyses using other polymorphisms of the CCKBR gene and Japanese samples, the present results exclude a major genetic contribution of the CCKBR gene to susceptibilities to panic disorder and schizophrenia in Japanese cohorts." [Abstract]

Hösing VG, Schirmacher A, Kuhlenbäumer G, Freitag C, Sand P, Schlesiger C, Jacob C, Fritze J, Franke P, Rietschel M, Garritsen H, Nöthen MM, Fimmers R, Stögbauer F, Deckert J
Cholecystokinin- and cholecystokinin-B-receptor gene polymorphisms in panic disorder.
J Neural Transm Suppl. 2004;(68):147-56.
Panic disorder like other neuropsychiatric disorders is believed to be caused by multiple psychosocial and biological factors. Several lines of evidence point to a role for the peptide neurotransmitter cholecystokinin in the pathogenesis of panic disorder. We therefore determined the allele and genotype frequencies of a single nucleotide polymorphism in the CCK gene (-36C>T) and one CT repeat polymorphism in the CCK-B-receptor gene in a German panic disorder sample (n = 115 for CCK gene polymorphism, n = 111 for CCK-B-receptor polymorphism) and compared them with gender and age matched controls. The length of the polymorphic CT repeat alleles varies between 146 bp and 180 bp. We first analysed the results by a permutation test which provided evidence for heterogeneity between patients and controls (p=0.002). We then analysed the data as a di-allelic polymorphism with a short (146-162bp) and a long (164-180bp) allele and as a tetra-allelic polymorphism with 4 alleles (146-154bp, 156-162bp, 164-170bp, 172-180bp). In the di-allelic analysis as well as in the tetra-allelic analysis there was an excess of the longer allele (p = 0.001) or the two longer alleles (p = 0.041) respectively in patients with panic disorder. No difference between groups was observed for the -36C > T polymorphism. Our findings are consistent with the notion that genetic variation in the CCK neurotransmitter system contributes to the pathogenesis of panic disorder. [Abstract]

Hansen TV, Rehfeld JF, Nielsen FC.
Function of the C-36 to T polymorphism in the human cholecystokinin gene promoter.
Mol Psychiatry 2000 Jul;5(4):443-7
"Cholecystokinin (CCK) is the most abundant neuropeptide in the mammalian brain, and in man significant quantities are expressed in all regions of the brain.1,2 Therefore, CCK has been implicated in a variety of CNS functions-such as feeding behavior, anxiety, analgesia and memory functions as well as psychiatric disease like panic disorder and schizophrenia (for review, see2,3). Recently, a number of studies have indicated that a C-36 to T transition in the CCK gene promoter Sp1 element4 (Figure 1) is associated with alcoholism and withdrawal symptoms as well as panic disorder.5-7 Moreover, it has been proposed that the polymorphism plays a direct role in the pathogenesis of the disorders by decreasing the expression and synthesis of CCK peptides. The significance of these findings is still unclear and other studies have failed to demonstrate linkage between the polymorphism and alcoholism.8 In this study we examined the function of the C-36 to T transition in transcription of the human CCK gene. We demonstrate that substitution of the C-36 residue causes a slight reduction of Sp1 and Sp3 binding, but this has no effect on transcription in vivo. Moreover, no difference in the response to physiological stimuli was observed. Taken together the results show that the C to T polymorphism does not play a direct role in the pathogenesis of either alcoholism or panic disorder and that a putative association to these disorders is likely to be the result of co-segregation with a linked mutation." [Abstract]

Hamilton SP, Slager SL, Helleby L, Heiman GA, Klein DF, Hodge SE, Weissman MM, Fyer AJ, Knowles JA.
No association or linkage between polymorphisms in the genes encoding cholecystokinin and the cholecystokinin B receptor and panic disorder.
Mol Psychiatry 2001 Jan;6(1):59-65
"Growing animal data implicate cholecystokinin in the regulation of anxiety, while human clinical research confirms the role of cholecystokinin in the provocation of panic attacks. Antipanic medications suppress the ability of cholecystokinin to induce panic attacks, and may alter the expression of the cholecystokinin gene. Thus, there is increased interest in understanding the molecular genetic component of these observations. Recent association studies using persons with panic disorder described some association between polymorphisms in the genes encoding cholecystokinin and the cholecystokinin B-receptor and panic disorder. In this study, we used a family-based design, employing 596 individuals in 70 panic disorder pedigrees, as well as 77 haplotype relative risk 'triads'. Subjects were genotyped for two polymorphisms: the polymorphic microsatellite marker in the CCK-BR locus using PCR-based genotyping and at a single nucleotide polymorphism in the CCK promoter using a fluorescence polarization detection assay, and the data were analyzed for genetic association and linkage. Employing a variety of diagnostic and genetic models, linkage analysis produced no significant lod scores at either locus. Family-based tests of association, the haplotype-based haplotype relative risk statistic and the transmission disequilibrium test, were likewise non-significant. The results reported here provide little support for the role of these polymorphisms in panic disorder." [Abstract]

Ise K, Akiyoshi J, Horinouchi Y, Tsutsumi T, Isogawa K, Nagayama H.
Association between the CCK-A receptor gene and panic disorder.
Am J Med Genet 2003 Apr 1;118B(1):29-31
"Cholecystokinin (CCK) is one of the most abundant neurotransmitter peptides in the brain. CCK appears to play an important role in the neurobiology of anxiety and panic disorders (PD) in both humans and animals. Recently, we reported that lack of CCKAR had a significant anxiogenic-like effect in rats. In this study, to investigate the role of CCKAR in PD, we compared the CCKAR gene in PD patients and normal controls. Subjects who fulfilled the DSM-IV criteria for PD were 17 males and 26 females. The sequence containing the Pst I polymorphic site in the boundary between intron 1 and exon 2 of the CCKAR gene was studied. Pst I digestion of the PCR products gave two individual alleles: A1 and A2. The A1 allele was the undigested fragment and the A2 allele was the digested one with two variant bands at 264 and 180 bp. Genotypic frequencies were 20.9% (A1-A1), 55.8% (A1-A2), and 41.7% (A2-A2) in patients, and 20.5% (A1-A1), 46.2% (A1-A2), and 33.3% (A2-A2) in controls. Allelic frequencies were 48.8% (A1) and 51.2% (A2) in patients, and 43.6% (A1) and 56.4% (A2) in controls. The chi-square test did not show a significant difference in either genotypic or allelic frequencies between patients and control subjects. The Pst polymorphism of CCKAR may not be associated with PD." [Abstract]

Kato T, Wang ZW, Zoega T, Crowe RR.
Missense mutation of the cholecystokinin B receptor gene: lack of association with panic disorder.
Am J Med Genet 1996 Jul 26;67(4):401-5
"Cholecystokinin tetrapeptide (CCK4) is known to induce panic attacks in patients with panic disorder at a lower dose than in normal controls. Therefore, the cholecystokinin B (CCKB) receptor gene is a candidate gene for panic disorder. We searched for mutations in the CCKB gene in 22 probands of panic disorder pedigrees, using single-strand conformation polymorphism (SSCP) analysis. Two polymorphisms were detected. A polymorphism in an intron (2491 C-->A) between exons 4 and 5 was observed in 10 of 22 probands. A missense mutation in the extracellular loop of exon 2 (1550 G-->A, Val125-->Ile) was found in only one proband. This mutation was also examined in additional 34 unrelated patients with panic disorder and 112 controls. The prevalence rate of this mutation was 8.8% in patients with panic disorder (3/34) and 4.4% in controls (5/112). The mutation did not segregate with panic disorder in two families where this could be tested. These results suggest no pathophysiological significance of this mutation in panic disorder." [Abstract]

Woo JM, Yoon KS, Choi YH, Oh KS, Lee YS, Yu BH
The association between panic disorder and the L/L genotype of catechol-O-methyltransferase.
J Psychiatr Res. 2004 Jul-Aug;38(4):365-70.
To clarify the role of catechol-O-methyltransferase (COMT) polymorphism in panic disorder (PD), we investigated a large group of Korean PD patients (N = 178) and controls (N = 182) using a case-control study. We also assessed the response to paroxetine treatment and other clinical variables in the PD patients. The increase in the COMT(L) allele was not statistically significant in PD (p = 0.104). However, compared with the sum of the other genotypes, the frequency of the L/L genotype was significantly higher in PD (p = 0.042). The odd ratios (ORs) also indicated a significant effect of the homozygosity for the COMT(L) allele on an increased risk for PD (OR=2.38; 95% CI 1.03-5.51). In addition, patients with L/L genotype had higher trait-anxiety levels (p = 0.030) and poorer treatment response to paroxetine than those with other genotypes (p = 0.002). Our results suggest that the COMT L/L genotype is associated with PD and the genetic variant of the COMT enzyme may be related to the clinical severity and treatment response to paroxetine in PD. [Abstract]

Woo JM, Yoon KS, Yu BH.
Catechol O-methyltransferase genetic polymorphism in panic disorder.
Am J Psychiatry 2002 Oct;159(10):1785-7
"OBJECTIVE: The authors examined the distribution of catechol O-methyltransferase (COMT) genotypes in patients with panic disorder as well as the relationship between a COMT polymorphism and the clinical characteristics of these patients. METHOD: Fifty-one patients with panic disorder and 45 healthy comparison subjects were tested for a genetic polymorphism of COMT. Clinical variables were assessed for the patients with panic disorder. RESULTS: The frequency of the L/L genotype was significantly higher in the patients with panic disorder than in the healthy subjects (19.6% versus 2.2%). Panic disorder was significantly associated with the L allele and L/L genotype. Patients with panic disorder who had the L/L genotype showed poorer treatment response than those with other genotypes. CONCLUSIONS: These results suggest that the L/L genotype of the COMT gene may be related to the development and treatment outcome of panic disorder in some patients." [Abstract]

Hamilton SP, Slager SL, Heiman GA, Deng Z, Haghighi F, Klein DF, Hodge SE, Weissman MM, Fyer AJ, Knowles JA.
Evidence for a susceptibility locus for panic disorder near the catechol-O-methyltransferase gene on chromosome 22.
Biol Psychiatry 2002 Apr 1;51(7):591-601
"BACKGROUND: A well-characterized single nucleotide polymorphism (472G/A-Val/Met-SNP8) in the coding sequence of the catechol-O-methyltransferase (COMT) gene leads to a three- to fourfold difference in enzymatic activity and clinical and animal studies suggest a role in anxiety states like panic disorder. METHODS: Subjects from 70 panic disorder pedigrees, and 83 "triads", were genotyped at seven single nucleotide polymorphisms (SNPs), polymorphic microsatellites in the first intron of COMT and approximately 339kb upstream of COMT (D22S944) and analyzed for genetic association and linkage. RESULTS: Linkage analysis showed elevated LOD scores for 472G/A (SNP 8), silent exon 3 substitution (186C/T-SNP 5), and the marker D22S944 (2.88, 2.62, and 2.93, respectively), using a variety of diagnostic and genetic models. Association tests were not significant for the SNPs, but were highly significant for D22S944 (p =.0001-.0003). One three-marker haplotype formed from the above three polymorphisms was significantly associated with panic disorder (p =.0001), as was the "global" p value for this combination (p =.005). In addition, numerous haplotypes with combinations of D22S944 and COMT SNPs were found to be significantly associated with panic disorder. CONCLUSIONS: Our findings provide strong evidence for a susceptibility locus for panic disorder either within the COMT gene or in a nearby region of chromosome 22." [Abstract]

Rothe C, Koszycki D, Bradwejn J, King N, Deluca V, Tharmalingam S, Macciardi F, Deckert J, Kennedy JL
Association of the Val158Met Catechol O-Methyltransferase Genetic Polymorphism with Panic Disorder.
Neuropsychopharmacology. 2006 Mar 8;
Genetic as well as clinical data suggest that catechol O-methyltransferase (COMT) is involved in multiple complex psychiatric conditions. Recent studies have described an association between the Val158Met COMT polymorphism and panic disorder. Other recent investigations provide evidence that there are other loci within or nearby the COMT gene that may contribute to the susceptibility to panic disorder. To further evaluate the influence of the Val158Met COMT polymorphism in panic disorder we genotyped this marker in the coding region of the COMT gene and two additional variants (rs737865 and rs165599) in the 5' and the 3' region, respectively, in two independent Canadian samples: 121 nuclear families, and 89 cases with matched controls. In the nuclear families, significant transmission disequilibrium for the valine allele was observed between the alleles of the Val158Met COMT polymorphism and panic disorder (p<0.01). A significant excess of the valine allele was found in analysis of the case-control sample (p<0.01). This effect was mainly derived from the subgroup of females. This finding, including the female effect, replicates earlier results in studies of the Val158Met polymorphism in panic disorder. No significant results were found for the other two markers. These results support the hypothesis that the valine allele of the Val158Met COMT polymorphism or a nearby locus is involved in the etiopathogenesis of panic disorder. [Abstract]

Olsson CA, Anney RJ, Lotfi-Miri M, Byrnes GB, Williamson R, Patton GC
Association between the COMT Val158Met polymorphism and propensity to anxiety in an Australian population-based longitudinal study of adolescent health.
Psychiatr Genet. 2005 Jun;15(2):109-15.
OBJECTIVES: Catechol-O-methyltransferase plays a central role in the metabolism of biogenic amines such as norepinephrine, dopamine and serotonin. Functional studies have demonstrated a dose relationship between ValMet genotypes and catechol-O-methyltransferase activity. Compared with the ValVal genotype, the ValMet and MetMet genotypes result in two- and four-fold reductions in catechol-O-methyltransferase activity, respectively. Two recent reports have observed the association between the MetMet genotype and risk of anxiety in adult populations. We examined the association between the ValMet genotypes and propensity to anxiety across adolescence. METHODS: Participants were drawn from an eight-wave study of the mental and behavioural health of over 2000 young Australians followed from 14 to 24 years of age (Victorian Adolescent Health Cohort Study, 1992 to present). DNA was received from 962 participants using a cheek swab collection method. RESULTS: The odds of reporting persistent episodic anxiety (phobic avoidance, panic attacks) were doubled among carriers of the MetMet genotype (odds ratio 2.0, 95% confidence interval 1.1-3.4, P=0.014). A dose relationship between additional copies of the Met allele and persistent episodic anxiety was also observed (1.5, 1.1-1.94, P=0.007). Stratification by sex showed that the risk effect of the Met allele was among females only. No association was observed for measures of neuroticism, persistent generalized anxiety, or a composite measure of psychiatric distress. CONCLUSION: These data replicate previous findings suggesting association between the ValMet polymorphism and specific expressions of anxiety among females. [Abstract]

Domschke K, Freitag CM, Kuhlenbäumer G, Schirmacher A, Sand P, Nyhuis P, Jacob C, Fritze J, Franke P, Rietschel M, Garritsen HS, Fimmers R, Nöthen MM, Lesch KP, Stögbauer F, Deckert J
Association of the functional V158M catechol-O-methyl-transferase polymorphism with panic disorder in women.
Int J Neuropsychopharmacol. 2004 Jun;7(2):183-8.
Panic disorder is an anxiety disorder with an estimated heritability of up to 48%. Pharmacological and genetic studies suggest that genes coding for proteins involved in the catecholaminergic system might be relevant for the pathogenesis of the disease. In the present study, we genotyped a single nucleotide polymorphism (472G/A=V158M) in the coding region of the catechol-O-methyl-transferase (COMT) gene in 115 patients with panic disorder and age- and sex-matched controls. Association analysis revealed a significant excess of the more active COMT allele (472G=V158) in patients with panic disorder (p=0.04), particularly in female patients (p=0.01), but not in male patients (p=1.0). The assessment of a possible interaction of the COMT polymorphism with a previously reported functional 30-bp VNTR in the monoamine oxidase A promoter (MAOALPR) in female patients did not yield significant results. Our data support a role of the 472G/A (V158M) COMT polymorphism or a nearby locus in the pathogenesis of panic disorder in women. [Abstract]

Rotondo A, Mazzanti C, Dell'Osso L, Rucci P, Sullivan P, Bouanani S, Gonnelli C, Goldman D, Cassano GB.
Catechol o-methyltransferase, serotonin transporter, and tryptophan hydroxylase gene polymorphisms in bipolar disorder patients with and without comorbid panic disorder.
Am J Psychiatry 2002 Jan;159(1):23-9
"OBJECTIVE: Genetic epidemiologic and clinical data suggest that comorbid panic disorder may define a subtype of bipolar disorder. Comorbid panic disorder might thereby influence the strength of association between bipolar disorder and genes that have been implicated in bipolar disorder on the basis of their function in monoamine neurotransmission and previously reported linkage results. Polymorphic markers at catechol O-methyltransferase (COMT), serotonin transporter (5-HTT), and tryptophan hydroxylase (TPH) genes were analyzed in a case-control association study of bipolar disorder patients with or without lifetime panic disorder. METHOD: Unrelated subjects of Italian descent meeting DSM-III-R criteria for lifetime bipolar disorder (N=111), with (N=49) or without (N=62) comorbid lifetime panic disorder, were compared to 127 healthy subjects. DNA was extracted from blood leukocytes. The frequencies of COMT Val158Met, 5-HTTLPR, and TPH IVS7+218C>A polymorphisms were determined. Genotype and allele frequency comparisons between affected (bipolar disorder, bipolar disorder without panic disorder, or bipolar disorder with panic disorder) and unaffected individuals were carried out with chi-square tests or Fisher's exact tests. RESULTS: Relative to the comparison subjects, subjects with bipolar disorder without panic disorder, but not those with comorbid bipolar disorder and panic disorder, showed significantly higher frequencies of the COMT Met158 and the short 5-HTTLPR alleles and genotypes. The differences in the frequencies of the TPH IVS7+218A alleles and genotypes approached statistical significance. CONCLUSIONS: The findings support the hypothesis that comorbid panic disorder identifies a genetic subtype of bipolar disorder and suggest a role for COMT and 5-HTT in vulnerability to these disorders." [Abstract]

Leygraf A, Hohoff C, Freitag C, Willis-Owen SA, Krakowitzky P, Fritze J, Franke P, Bandelow B, Fimmers R, Flint J, Deckert J
Rgs 2 gene polymorphisms as modulators of anxiety in humans?
J Neural Transm. 2006 Jun 1;
Rgs2 (regulator of G-protein signalling 2) gene recently was reported as a quantitative trait gene for anxious behaviour in mice and male Rgs2 knockout mice have been shown to be more anxious than wildtype mice. Therefore we investigated four non-coding single nucleotide polymorphisms in a sample of 173 patients with panic disorder and 173 matched controls of German descent. At the genotype level all four SNPs were associated with panic disorder (p = 0.02-0.05). At the haplotype level the strongest association was observed for a haplotype containing SNP3 and SNP 4 (subgroup men and men with agoraphobia: p = 0.01 and 0.03). This points towards a functional polymorphism at the 3' end of the gene. Our results support the hypothesis that variations of the Rgs2 gene play a role also for the development of anxiety in humans. [Abstract]

Ho HP, Westberg L, Annerbrink K, Olsson M, Melke J, Nilsson S, Baghaei F, Rosmond R, Holm G, Björntorp P, Andersch S, Allgulander C, Eriksson E
Association between a functional polymorphism in the progesterone receptor gene and panic disorder in women.
Psychoneuroendocrinology. 2004 Oct;29(9):1138-41.
Although genetic factors are known to be important risk factors for panic disorder there is as yet no conclusive data regarding specific gene variants. Prompted by evidence supporting progesterone to influence the pathophysiology of panic disorder, polymorphisms in the progesterone receptor gene, a single nucleotide polymorphism (G331A) and an insertion/deletion polymorphism (PROGINS) were investigated in 72 patients with panic disorder and 452 controls. The frequency of the A-allele of the G331A polymorphism was higher in panic disorder patients than in controls (p = 0.01). When male and female patients were analyzed separately, the association was observed in female patients only (p = 0.0009), with an odds ratio of 3.5. No differences between groups were observed for the PROGINS polymorphism. In conclusion, these data suggest that the G331A polymorphism in the progesterone receptor gene may influence the risk for panic disorder in women. [Abstract]

Philibert RA, Nelson JJ, Sandhu HK, Crowe RR, Coryell WH.
Association of an exonic LDHA polymorphism with altered respiratory response in probands at high risk for panic disorder.
Am J Med Genet 2003 Feb 15;117B(1):11-7
"Panic disorder (PD) is a clinical syndrome characterized by recurrent discrete episodes of fear accompanied by a variety of physiological and psychological symptoms, often with prominent respiratory components. A series of clinical observations has led some investigators to hypothesize that subtle alterations in ventilatory regulation are integral to at least a subtype of PD. In order to identify genetic factors that might predispose individuals to these alterations in ventilatory response, we conducted single stranded conformation polymorphism analysis across the exons of the lactate dehydrogenase A and B genes (LDHA and LDHB) using DNA prepared from 86 subjects previously characterized by respiratory response to a CO(2) challenge with a variable genetic loading for PD. Remarkably, a single conserved LDHA exon 5 haplotype conferred increased risk for a paradoxical ventilatory response pattern to CO(2) inhalation which robustly separated well subjects at high risk for PD from low-risk control subjects. But, comparison of LDHA exon 5 genotypes in PD probands (n = 25) to that of random newborn controls (n = 182) did not demonstrate any significant differences. Given the pivotal role of LDH in the metabolism of lactate, a known inducer of panic attacks, and the dependence of LDH activity on cell pH, we suggest that LDHA polymorphisms may contribute to the variability to CO(2) respiratory challenge." [Abstract]

Crowe RR, Goedken R, Samuelson S, Wilson R, Nelson J, Noyes R Jr.
Genomewide survey of panic disorder.
Am J Med Genet 2001 Jan 8;105(1):105-9
"We completed a genome scan of 23 multiplex families of panic disorder. Ninety family members had DSM-III-R panic disorder, and another 23 had recurrent, spontaneous panic attacks that did not satisfy these criteria. We typed 469 markers from the CHLC map (ver 8c7) with an average intermarker distance of 10.3 cM. Two-point lod scores were calculated with both a dominant and a recessive model, and maps of lod scores < -2.00, assuming genetic homogeneity, were constructed by using DSM-III-R panic disorder as the affected phenotype. Lod scores were < -2.00 over 94-95% of the genome. The greatest lod score was 2.23 (theta = 0.15) at the D7S2846 locus, located at 57.8 cM on chromosome 7 according to the Marshfield Clinic map. Flanking markers analyzed in a nonparametric, multipoint analysis using GENEHUNTER resulted in an NPL score of 2.97 at 63 cM on the Marshfield map. This region lies within 15 cM from the D7S435 locus, where Knowles et al. [1998] obtained a lod score of 1.71 (theta = 0.10) for panic disorder (now 2.45 with the addition of new families; James Knowles, personal communication). Thus, the maximum evidence of linkage from two genome scans of panic disorder lies within a small region of chromosome 7p." [Abstract]

Hamilton SP, Fyer AJ, Durner M, Heiman GA, Baisre de Leon A, Hodge SE, Knowles JA, Weissman MM.
Further genetic evidence for a panic disorder syndrome mapping to chromosome 13q.
Proc Natl Acad Sci U S A 2003 Mar 4;100(5):2550-5
"Substantial evidence supports that there is a genetic component to panic disorder (PD). Until recently, attempts at localizing genes for PD by using standard phenotypic data have not proven successful. Previous work suggests that a potential subtype of PD called the panic syndrome exists, and it is characterized by a number of medical conditions, most notably bladder/renal disorders. In the current study, a genome scan with 384 microsatellite markers was performed on 587 individuals in 60 multiplex pedigrees segregating PD and bladder/kidney conditions. Using both single-locus and multipoint analytic methods, we found significant linkage on chromosome 22 (maximum heterogeneity logarithm of odds score = 4.11 at D22S445) and on chromosome 13q (heterogeneity logarithm of odds score = 3.57 at D13S793) under a dominant-genetic model and a broad phenotypic definition. Multipoint analyses did not support the observation on chromosome 22. The chromosome 13 findings were corroborated by multipoint findings, and extend our previous findings from 19 of the 60 families. Several other regions showed elevated scores by using when one analytic method was used, but not the other. These results suggest that there are genes on chromosome 13q, and possibly on chromosome 22 as well, that influence the susceptibility toward a pleiotropic syndrome that includes PD, bladder problems, severe headaches, mitral valve prolapse, and thyroid conditions." [Abstract]

Smoller JW, Acierno JS Jr, Rosenbaum JF, Biederman J, Pollack MH, Meminger S, Pava JA, Chadwick LH, White C, Bulzacchelli M, Slaugenhaupt SA.
Targeted genome screen of panic disorder and anxiety disorder proneness using homology to murine QTL regions.
Am J Med Genet 2001 Mar 8;105(2):195-206
"Family and twin studies have indicated that genes influence susceptibility to panic and phobic anxiety disorders, but the location of the genes involved remains unknown. Animal models can simplify gene-mapping efforts by overcoming problems that complicate human pedigree studies including genetic heterogeneity and high phenocopy rates. Homology between rodent and human genomes can be exploited to map human genes underlying complex traits. We used regions identified by quantitative trait locus (QTL)-mapping of anxiety phenotypes in mice to guide a linkage analysis of a large multiplex pedigree (99 members, 75 genotyped) segregating panic disorder/agoraphobia. Two phenotypes were studied: panic disorder/agoraphobia and a phenotype ("D-type") designed to capture early-onset susceptibility to anxiety disorders. A total of 99 markers across 11 chromosomal regions were typed. Parametric lod score analysis provided suggestive evidence of linkage (lod = 2.38) to a locus on chromosome 10q under a dominant model with reduced penetrance for the anxiety-proneness (D-type) phenotype. Nonparametric (NPL) analysis provided evidence of linkage for panic disorder/agoraphobia to a locus on chromosome 12q13 (NPL = 4.96, P = 0.006). Modest evidence of linkage by NPL analysis was also found for the D-type phenotype to a region of chromosome 1q (peak NPL = 2.05, P = 0.035). While these linkage results are merely suggestive, this study illustrates the potential advantages of using mouse gene-mapping results and exploring alternative phenotype definitions in linkage studies of anxiety disorder." [Abstract]

MacKinnon DF, Xu J, McMahon FJ, Simpson SG, Stine OC, McInnis MG, DePaulo JR.
Bipolar disorder and panic disorder in families: an analysis of chromosome 18 data.
Am J Psychiatry 1998 Jun;155(6):829-31
"OBJECTIVE: The authors performed an analysis of their published chromosome 18 linkage data on 28 families in which there was bipolar disorder to test the potential of comorbid panic disorder to define a genetic subtype of bipolar disorder. METHOD: Families ascertained through probands with bipolar I disorder were stratified into three groups based on a history of panic disorder, panic attacks, or no panic attacks in the probands. Multipoint nonparametric linkage analysis was performed on data from bipolar I and II family members in each group. RESULTS: Linkage scores for five consecutive 18q marker loci were highest in the families of the probands with panic disorder and lowest for the families of the probands without panic attacks. CONCLUSIONS: This study supports the authors' previously reported clinical hypothesis of a genetic subtype of bipolar disorder identified by comorbid panic disorder. The hypothesis merits prospective testing." [Abstract]

Politi P, Minoretti P, Falcone C, Martinelli V, Emanuele E
Association analysis of the functional Ala111Glu polymorphism of the glyoxalase I gene in panic disorder.
Neurosci Lett. 2006 Mar 27;396(2):163-6.
The zinc metalloenzyme glyoxalase I (GLO1) is thought to play a role in anxiety disorders because a reduced brain expression of GLO1 has been associated with increased anxiety-behaviours in mice. Recently, a functional Ala111Glu polymorphism in GLO1 has been shown to result in a reduced enzyme activity. The present study tested the hypothesis that this common genetic variant could confer susceptibility to panic disorder using an Italian population sample of 162 panic disorder patients and 288 matched controls. Statistical analysis failed to show association with the overall diagnosis of the disease. However, a weak but significant association was demonstrated between this polymorphism and panic disorder without agoraphobia. While our data suggest that this polymorphism is unlikely to have a major function in the pathogenesis of panic disorder, it could play a role in the subgroup of patients without agoraphobic avoidance. [Abstract]

Schumacher J, Abou Jamra R, Becker T, Klopp N, Franke P, Jacob C, Sand P, Fritze J, Ohlraun S, Schulze TG, Rietschel M, Illig T, Propping P, Cichon S, Deckert J, Nöthen MM
Investigation of the DAOA/G30 locus in panic disorder.
Mol Psychiatry. 2005 May;10(5):428-9. [Abstract]

Yamada K, Hattori E, Shimizu M, Sugaya A, Shibuya H, Yoshikawa T.
Association studies of the cholecystokinin B receptor and A2a adenosine receptor genes in panic disorder.
J Neural Transm 2001;108(7):837-48
"Several lines of evidence implicate the cholecystokinin B receptor (CCKBR) and the A2a adenosine receptor (A2aAR) in the etiology of panic disorder. To determine the roles each of these receptors may play in panic disorder, we have performed a mutation screen on the CCKBR gene using single strand conformation polymorphism (SSCP) analysis and sequencing. We identified two novel but rare substitutions in the same allele, [3263G>C; 3264A>G], located in the 3'-untranslated region of the CCKBR gene. We then analyzed 91 unrelated patients and 100 matched controls for the four confirmed polymorphic sites in the CCKBR gene and the 1083C>T polymorphism in the A2aAR gene. No evidence of association between the described variants and panic disorder was found. Our data therefore suggests that the CCKBR and A2aAR genes do not play major roles in the development of this disease." [Abstract]

Lam P, Hong CJ, Tsai SJ
Association study of A2a adenosine receptor genetic polymorphism in panic disorder.
Neurosci Lett. 2005 Apr 18;378(2):98-101.
The adenosine A2a receptor (A2aAR) is thought to be implicated in the pathogenesis of panic disorder because caffeine, a potent antagonist for A2aAR, can precipitate panic attacks, and because disruption of the A2aAR gene increased anxiety-behaviors in mice. Recent studies demonstrated that the A2aAR 1976T > C genetic variant confers susceptibility to panic disorder though not by all studies. The present study tested the hypothesis that the A2aAR 1976T > C genetic variant confers susceptibility to panic disorder using a Chinese population of 104 panic disorder patients and 192 normal controls. We also tested whether the A2aAR 1976T > C polymorphism relates to the age of onset or subtype of panic disorders. Neither the distribution of the A2aAR 1976T > C genotypes (P = 0.296) or alleles (P = 0.864), nor the age of onset (P = 0.719) were significantly different among genotype groups. Furthermore, no association was demonstrated between this A2aAR polymorphism and either mitral-valve prolapse or agoraphobia in panic-disorder patients. These findings suggested that it is unlikely that the A2aAR 1976T > C polymorphism plays a major role in panic disorder pathogenesis in the Chinese population. The positive association between this polymorphism and panic disorder found in western population but not in Asian population suggests that this association could be ethnicity-dependent. The 1976C > T polymorphism may be in linkage disequilibrium with a functional variant that affects panic disorder, and the extent of this linkage disequilibrium is not similar for all ethnic populations. [Abstract]

Hamilton SP, Slager SL, De Leon AB, Heiman GA, Klein DF, Hodge SE, Weissman MM, Fyer AJ, Knowles JA
Evidence for genetic linkage between a polymorphism in the adenosine 2A receptor and panic disorder.
Neuropsychopharmacology. 2004 Mar;29(3):558-65.
Data from clinical and behavioral pharmacological studies have implicated adenosine in anxiety behaviors, while genetic studies have suggested that adenosine receptors may be associated with panic disorder. We have undertaken an analysis of several DNA sequence variations in the adenosine 2A receptor (ADORA2A) in a large sample of panic disorder pedigrees. Individuals from 70 panic disorder pedigrees, and 83 child-parent 'trios', were genotyped at five single-nucleotide polymorphisms (SNPs) in and near the ADORA2A gene and were analyzed for genetic linkage and association. Linkage analysis revealed elevated LOD scores for a silent substitution (1083C/T, SNP-4) in the second coding exon. This SNP has been previously reported to be associated with panic disorder. We observed a maximal heterogeneity LOD score of 2.98 (theta=0) under a recessive genetic model and narrow diagnostic model. Other SNPs showed no evidence for linkage. Association tests were not significant for any of the five ADORA2A SNPs. When SNP haplotypes were assessed in the triads with TRANSMIT, one 3-marker haplotype (SNPs 1, 4, 5) was nominally significantly associated with panic disorder (p=0.029). Pairwise estimations of linkage disequilibrium between the SNPs showed strong patterns of linkage disequilibrium across the ADORA2A locus. Analyses carried out by broadening the panic disorder phenotype to include agoraphobia continued to support linkage to ADORA2A. Our findings provide evidence for a susceptibility locus for panic disorder, and possibly including agoraphobia, either within the ADORA2A gene or in a nearby region of chromosome 22, and serves as the first successful candidate gene replication study in panic disorder. [Abstract]

Deckert J, Nothen MM, Franke P, Delmo C, Fritze J, Knapp M, Maier W, Beckmann H, Propping P.
Systematic mutation screening and association study of the A1 and A2a adenosine receptor genes in panic disorder suggest a contribution of the A2a gene to the development of disease.
Mol Psychiatry 1998 Jan;3(1):81-5
"Several lines of evidence suggest a contribution of adenosinergic neurotransmission to the development of panic disorder. We therefore hypothesized that variation in the A1 and A2a adenosine receptor (AR) genes modifies genetic susceptibility to panic disorder. To test this hypothesis, we screened 38 patients with panic disorder for mutations in the coding sequence of the A1AR and A2aAR genes. An association study between the identified DNA sequence variants and panic disorder was performed in an extended sample of 89 patients and matched controls. One silent mutation (716T/G) in the A1AR gene and two silent mutations (432C/T and 1083C/T) in the A2aAR gene were detected. The association sample shows a significant association between the 1083T allele (P=0.01) and 1083T/T genotype (P=0.024) of the A2AR gene and panic disorder. Our findings thus lend further support to the hypothesis that the A2aAR gene, or a locus in linkage disequilibrium with it, confers susceptibility to panic disorder. Replication studies in independent samples with nuclear families applying the transmission disequilibrium test (TDT) are warranted." [Abstract]

Olsson M, Annerbrink K, Westberg L, Melke J, Baghaei F, Rosmond R, Holm G, Andersch S, Allgulander C, Eriksson E
Angiotensin-related genes in patients with panic disorder.
Am J Med Genet B Neuropsychiatr Genet. 2004 May 15;127(1):81-4.
Enhanced respiratory variability and decreased heart rate variability have repeatedly been observed in patients with panic disorder. Prompted by the notion that angiotensin may be involved in the control of respiration, heart rate variability, and anxiety-like behavior, we investigated the putative association between polymorphisms in three angiotensin-related genes and panic disorder-angiotensinogen (AGT), angiotensin converting enzyme (ACE), and angiotensin II (ANG II) receptor type 1 (ATr1) in 72 patients with panic disorder and 504 controls. Allele and genotype distribution of the ATr1 A1166C allele and the AGT M235T did not differ between patients and controls. With respect to the ACE I/D polymorphism, the I allele was found to be more frequent in male (chi(2) = 8.042, df = 1, P = 0.005), but not female, panic disorder patients than in controls. The results of this investigation provide preliminary evidence for the suggestion that angiotensin-related genes may be associated with panic disorder in men. [Abstract]

Shimizu E, Hashimoto K, Kobayashi K, Mitsumori M, Ohgake S, Koizumi H, Okamura N, Koike K, Kumakiri C, Nakazato M, Komatsu N, Iyo M
Lack of association between angiotensin I-converting enzyme insertion/deletion gene functional polymorphism and panic disorder in humans.
Neurosci Lett. 2004 Jun 3;363(1):81-3.
Family and twin studies have indicated that genes influence susceptibility to panic disorder, but the genes involved remain unknown. The neuropeptide angiotensin II has been found to be involved in anxiety and regulation of respiration which are important in the pathophysiology of panic attacks. Assuming that angiotensins may be candidate genes in panic disorder, we analyzed the association between panic disorder and angiotensin I-converting enzyme (ACE) insertion (I)/deletion (D) gene functional polymorphism. We recruited 101 patients with panic disorder diagnosed according to DSM-IV criteria, and 184 control subjects in the study. No significant differences in the frequency of the genotype or allele in the polymorphism between patient and control groups were found (genotype, chi(2)=0.56, d.f.=2, P=0.77; allele, chi(2)=0.074, d.f.=1, P=0.78). This study suggests that the ACE I/D gene polymorphism is not directly associated with panic disorder in our Japanese patient group. [Abstract]

Hamilton SP, Slager SL, Mayo D, Heiman GA, Klein DF, Hodge SE, Fyer AJ, Weissman MM, Knowles JA
Investigation of polymorphisms in the CREM gene in panic disorder.
Am J Med Genet B Neuropsychiatr Genet. 2004 Apr 1;126(1):111-5.
Clinical and animal studies suggest a role for pathways regulated by cyclic-AMP in anxiety. Mouse gene deletion studies, our own linkage findings on chromosome 10, and a recently published genetic association study by Domschke et al. [2003: Am J Med Genet 117B:70-78] suggest that the cAMP responsive element modulator (CREM) may be involved in panic disorder. We have employed a family-based design to investigate the role of DNA sequence variations in the gene for CREM in panic disorder. We have genotyped 613 individuals in 70 panic disorder pedigrees, as well as 42 parent/offspring triads. Subjects were genotyped at two informative single nucleotide polymorphisms (SNPs) and three polymorphic microsatellites in the CREM genomic region; and the data were analyzed for genetic association and linkage. Linkage analysis employing several diagnostic/genetic models produced a maximum lod score of 0.63 for SNP-1, located in the 5' UTR of CREM, under a dominant model with a broad diagnostic definition of panic disorder. Non-parametric analysis, using the NPL statistic or FBAT, also did not support any linkage or association between the markers and panic disorder. All five markers (spanning 77 kb) used in the study showed modest, but significant linkage disequilibrium. Analysis of 2-, 3-, 4-, or 5-marker haplotypes using TRANSMIT failed to find any globally significant results; however, individual haplotypes containing a single allele of MS-3 were nominally associated with panic disorder. These findings provide little additional evidence for a susceptibility locus for panic disorder either within the CREM gene or in a nearby region of chromosome 10p11 in our sample. [Abstract]

Lindberg C, Koefoed P, Hansen ES, Bolwig TG, Rehfeld JF, Mellerup E, Jørgensen OS, Kessing LV, Werge T, Haugbøl S, Wang AG, Woldbye DP
No association between the -399 C > T polymorphism of the neuropeptide Y gene and schizophrenia, unipolar depression or panic disorder in a Danish population.
Acta Psychiatr Scand. 2006 Jan;113(1):54-8.
OBJECTIVE: A polymorphism in the promoter region of the NPY gene at position -399 C > T was recently reported to be associated with schizophrenia in a Japanese population and with treatment refractory unipolar depression in a Swedish population. The objective of this study was to investigate potential associations between the polymorphism and three psychiatric disorders in a Danish population. METHOD: We investigated the occurrence of the polymorphism in patients with schizophrenia (n = 291), unipolar depression (n = 256) and panic disorder (n = 142) compared with controls (n = 716). RESULTS: We detected the polymorphism -399 C > T at a frequency of 48% in controls. No significant differences were found between genotype or allele frequencies in controls vs. the patient groups. CONCLUSION: The lack of association between the -399 C > T polymorphism and schizophrenia, unipolar depression or panic disorder, respectively, suggests that the polymorphism is not involved in the etiology of these disorders in the Danish population. [Abstract]

Martínez-Barrondo S, Sáiz PA, Morales B, García-Portilla MP, Coto E, Alvarez V, Bascarán MT, Bousoño M, Bobes J
Negative evidences in association between apolipoprotein E polymorphism and panic disorder.
Eur Psychiatry. 2006 Jan;21(1):59-61.
The aim is to investigate the association between apolipoprotein E (ApoE) and panic disorder (PD). Genotyping 92 PD patients [Diagnostic Statistic Manual IV (DSM IV) criteria] and 174 controls no differences were found between both groups. Variation in the ApoE-gene was not associated with the development of PD. [Abstract]

Shimizu E, Hashimoto K, Koizumi H, Kobayashi K, Itoh K, Mitsumori M, Ohgake S, Okamura N, Koike K, Matsuzawa D, Zhang L, Kumakiri C, Nakazato M, Komatsu N, Iyo M
No association of the brain-derived neurotrophic factor (BDNF) gene polymorphisms with panic disorder.
Prog Neuropsychopharmacol Biol Psychiatry. 2005 Jun;29(5):708-12.
Several lines of evidence suggest that genetic factors might contribute to susceptibility to panic disorder. Our previous studies show that the brain-derived neurotrophic factor (BDNF) may play a role in the pathophysiology of major depressive disorders and eating disorders. Assuming that BDNF may be implicated in the putative common pathophysiology of depression and anxiety, we analyzed the association of two BDNF gene single nucleotide polymorphisms (SNPs), 132C > T (formerly named C270T) in the noncoding region of exon V and 196G > A (val66met) in the coding region of exon XIIIA, with panic disorder. In this study, 109 patients with panic disorder diagnosed according to the DSM-IV criteria, and 178 control subjects were recruited. There were no significant differences in the frequency of the genotype or allele in these two SNPs between patients and controls [132C > T in exon V: genotype, p = 1.0, allele, p = 0.59; 196G > A (val66met) in exon XIIIA: genotype, p = 0.77, allele, p = 0.78]. Furthermore, no significant associations of agoraphobia with the two SNPs were detected. This study suggests that the BDNF gene polymorphisms are not associated with panic disorder in our Japanese population. [Abstract]

Lam P, Cheng CY, Hong CJ, Tsai SJ
Association study of a brain-derived neurotrophic factor (Val66Met) genetic polymorphism and panic disorder.
Neuropsychobiology. 2004;49(4):178-81.
Brain-derived neurotrophic factor (BDNF), a member of the neurotrophic factor family, plays an important role in the development, maintenance and function of several neuronal systems. Recent studies have demonstrated that antidepressants, commonly used for panic disorder treatment, can increase central BDNF. In addition, animals with BDNF deficits have higher levels of anxiety when exposed to stressors in comparison to normal controls. The present study tested the hypothesis that the BDNF gene Val66Met polymorphism is associated with panic disorder. In this study, therefore, the incidence of this polymorphism was compared in 103 panic disorder patients and 180 normal controls. The genotype and allele frequencies for the BDNF gene Val66Met polymorphism did not differ comparing the two groups. Furthermore, no association was demonstrated between this BDNF polymorphism and either mitral valve prolapse or agoraphobia in panic disorder patients. These findings suggest that the investigated BDNF polymorphism does not play a major role in the pathogenesis of panic disorder in this Chinese population. Further studies exploring the relationship between genetic variations of BDNF and the cerebral atrophy associated with, and antidepressant treatment response in, panic disorder may be appropriate. [Abstract]

Hettema JM, Neale MC, Kendler KS.
A review and meta-analysis of the genetic epidemiology of anxiety disorders.
Am J Psychiatry 2001 Oct;158(10):1568-78
"OBJECTIVE: The authors conducted meta-analyses of data from family and twin studies of panic disorder, generalized anxiety disorder, phobias, and obsessive-compulsive disorder (OCD) to explore the roles of genetic and environmental factors in their etiology. METHOD: MEDLINE searches were performed to identify potential primary studies of these disorders. Data from studies that met inclusion criteria were incorporated into meta-analyses that estimated summary statistics of aggregate familial risk and heritability for each disorder. RESULTS: For family studies, odds ratios predicting association of illness in first-degree relatives with affection status of the proband (disorder present or absent) were homogeneous across studies for all disorders. The calculated summary odds ratios ranged fr