Lysyl oxidase-like 1 polymorphisms and exfoliation syndrome in the Japanese population

Abstract

Purpose: To investigate the contribution of two single-nucleotide polymorphisms (SNPs) of the lysyl oxidase-like 1 (LOXL1) gene, recently shown to be associated with exfoliation syndrome (XFS) and exfoliation glaucoma (XFG) in the Nordic population, to the occurrence of XFS and XFG in the Japanese population.

Design: Case-control association study.

Methods: A total of 59 unrelated Japanese individuals with XFS, 27 XFG patients, and 190 population-based controls were recruited. The SNPs rs1048661 (R141L) and rs3825942 (G153D) in the LOXL1 gene were genotyped directly. Association tests were performed for the two SNPs and inferred haplotypes.

Results: The frequency of the G allele in rs1048661, reportedly a functional risk allele in White persons, existed in only 0.8% of Japanese XFS cases, but occurred with much higher frequency in controls (46.0%) and yielded a P value of 3.0x10(-19), and the odds ratio for the T allele in rs1048661 was 99.8 (95% confidence interval, 13.8 to 722). For rs3825942, the frequency of the G allele, which is another possible risk allele in White persons with XFS, was 1.000 vs 0.857 in the controls (P=1.4x10(-5)). The most frequent haplotype in Japanese XFS patients was haplotype (T,G) (99.2%). The (G,G) haplotype, which generates the highest risk in White persons, was present in only a small percentage of Japanese XFS cases (0.8%).

Conclusions: The SNPs rs1048661 and rs3825942 of the LOXL1 gene seem to be highly associated with XFS in the Japanese population, but a different polymorphism of LOXL1 may cause the development of XFS in the Japanese population.