Replication of a genome-wide association study of panic disorder in a Japanese population

Panic disorder (PD) is an anxiety disorder characterized by recurrent and unexpected panic attacks, subsequent worry andphobic avoidance. Although a number of association and linkage studies have been conducted, no gene has been identified as asusceptibility locus. We previously conducted a genome-wide association analysis of PD in 200 Japanese patients and the samenumber of controls, using a 500K single nucleotide polymorphisms (SNPs) chip. In this study, we report a replication analysisof PD using the DigTag2 assay. The second stage sample consisted of 558 Japanese patients and 566 controls. Thirty-twomarkers were tested in a replication sample. As a result, no significant association was found after correction for multipletesting. However, the difference was observed at the nominal allele P-value o0.05 for two SNPs (rs6733840 and rs132617).We also conducted haplotype analyses of SNPs in the APOL3 and CLU genes. Our results failed to show any significantassociation with PD in these genes. Further studies on these variants with a larger sample size may be worth testing to confirmthe results.Journal of Human Genetics (2010) 55, 91–96; doi:10.1038/jhg.2009.127; published online 4 December 2009Keywords: genome-wide association study (GWAS); Japanese population; panic disorder; replication; single nucleotide polymorphism(SNP)INTRODUCTIONPanic disorder (PD) is an anxiety disorder characterized byrecurrent and unexpected panic attacks, subsequent worry andphobic avoidance. Life prevalence of PD is 1–3% and twice asmany women as men suffer from the disorder.