Likewise, the higher expressing LAC haplotype (5-HTTLPR/rs25531/rs25532) was more frequent in TD probands than in controls (P = 0.024; OR, 1.33) and also in the TD alone group versus the TD plus OCD group (P = 0.0013; OR, 2.14).
Haplotype-based testing of rs25532 and all other known non-coding functional SLC6A4 variants revealed a highly significant omnibus association with OCD in a large case-control sample.