Haplotype analyses, in contrast, revealed a highly significant omnibus association of 3 of these markers, rs3087879, rs301430, and rs7858819, with OCD (Table 2). In haplotype-specific tests (ie, when tested individually against all other haplotypes, with df=1), 3 of the 4 common haplotypes were nominally significant at P<.05. Two of these haplotypes remained significant after multiple-testing correction by permutation (Table 2). One haplotype, H4 in Table 2, was highly significant and almost twice as common in OCD than in controls (haplotype frequency, 9.4% vs 5.1%, respectively; odds ratio, 1.89; P=.001, family-wise permuted). We obtained similar—though not always as highly significant—results when we conducted these haplotype analyses stratified by sex (Table 2).
