To investigate whether variants in the LOC387715 locus and the HtrA serine peptidase 1 (HTRA1) gene within the 10q26 locus are associated with polypoidal choroidal vasculopathy (PCV) and wet age-related macular degeneration (AMD) in a Japanese population, and whether genetic diversity exists between PCV and wet AMD in this locus.

Cross-sectional study.

We genotyped 243 Japanese individuals, including 76 PCV cases, 73 wet AMD cases, and 94 controls using two single nucleotide polymorphisms (SNPs) that are located in the LOC387715 locus (rs10490924) or the HTRA1 gene (rs11200638). Genotyping was performed using TaqMan assays (Applied Biosystems, Foster City, California, USA).

Two SNPs generated highly significant allelic associations with PCV (rs10490924, P = 5.7 × 10⁻⁶; rs11200638, P = 5.2 × 10⁻⁶) and AMD (rs10490924, P = 1.4 × 10⁻⁶; rs11200638, P = 3.4 × 10⁻⁷). The odds ratios and population attributable risks were higher for the AMD cases than for the PCV cases. Homozygotes for the risk allele at rs11200638 had a 6.33-fold increased risk of PCV and a 13.77-fold increased risk of wet AMD when compared with homozygotes for the wild-type allele. There were no significant differences in either allelic or genotypic frequencies between PCV and AMD cases.

The LOC387715/HTRA1 variants are associated with PCV and wet AMD in the Japanese population. The associations are stronger in AMD than in PCV. PCV and AMD share common genetic factors, which suggests that PCV and wet AMD are similar in some pathophysiologic aspects.