A Case-Control Study of the Loxl1 Gene in Japanese Exfoliation Glaucoma Patients

Abstract

Purpose: : A recent study revealed the association between exfoliation glaucoma (XFG) and the single nucleotide polymorphisms (SNPs) rs1048661 and rs3825942, which are located in the first exon of LOXL1, in the Icelandic and Swedish populations. The purpose of this study was to investigate the association between XFG and these two SNPs in the Japanese population.

Methods: : Ninety-five Japanese XFG patients and 190 Japanese control subjects were recruited after complete ophthalmic examinations. Genomic DNA was obtained and genotyping was performed for the two SNPs by direct sequence. In addition, cDNAs were prepared from the anterior lens capsule from 10 XFG patients and 10 cataract control subjects, and real-time PCR was performed to quantify LOXL1 mRNA expression.

Results: : The frequencies of the rs1048661-G allele were 0.47 in the control subjects and 0.005 in the XFG patients (P=1.8x10^-28, Χ² test). The frequencies of the rs3825942-G allele were 0.85 in the control subjects and 0.99 in the XFG patients (P=9.5x10^-8). No difference in the amount of LOXL1 mRNA expression between XFG patients and cataract control subjects was observed.

Conclusions: : We found a strong genetic association between LOXL1 SNPs and XFG occurrence in the Japanese population. In contrast to the previous study in Iceland in which the G allele of rs1048661 was a risk factor, the T allele of rs1048661 was a strong risk allele for Japanese XFG.

Keywords: genetics