Several inconsistent associations between bipolar I disorder (BD1) and polymorphisms of the genes encoding the serotonin 2A receptor (HTR2A) have been published. We conducted the Transmission Disequilibrium Test (TDT) and case-control comparisons involving nine single nucleotide polymorphisms at the serotonin 2A receptor gene (four SNPs of HTR2A exons and five flanking SNPs). Comparison of BD1 cases (n = 93) with a group of unrelated population based controls (n = 92) revealed associations with SNPs on exons 2 and 3 (516C/T and 1354C/T, respectively), consistent with haplotype-based differences. Analysis of the cases and their available parents using the TDT suggested significant linkage and associations with 1354C/T, as well as haplotypes bearing this SNP. Our results support an etiological role for HTR2A in BD1. In view of the relatively small sample, replicate studies using large samples are needed.
Copyright 2003 Wiley-Liss, Inc.