Prevalence of risk alleles in the lysyl oxidase-like 1 gene in pseudoexfoliation glaucoma patients in India

Purpose: The purpose of this study was to genotype two previously identified SNPs (rs1048661:R141L, and rs3825942:G153D) in the lysyl oxidase-like 1 (LOXL1) gene and determine their association with pseudoexfoliation glaucoma (XFG) in patients from Pune, India.

Methods: All subjects underwent detailed phenotyping, and DNA extraction was performed on blood samples by using standardized techniques. Exon 1 of the LOXL1 gene containing the SNPs (rs3825942:G153D; rs1048661:R141L) were Sanger sequenced, and the results were analyzed using sequence analysis software SeqScape 2.1.1.

Results: Data were analyzed from 71 patients with XFG and 81 disease-negative, age-matched controls. There was a strong association between the G allele of rs3825942 and XFG with an odds ratio of 10.2 (CI: 3.92-26.6; P < 0.001). The G allele of rs1048661 also showed an increase in risk relative to the T allele (OR = 1.49; CI: 0.88-2.51; P = 0.13), but this was not significant. Haplotype combination frequencies were estimated for rs1048661 and rs3825942; the GG haplotype was associated with a significant increase in risk (OR = 3.91; CI: 2.27-6.73; P < 0.001). Both the GA and TG haplotypes were associated with decreased XFG risk, although the latter was not significant (GA: OR = 0.08; CI: 0.03-0.21; P < 0.001; TG: OR = 0.67; CI: 0.40-1.13; P = 0.13).

Conclusion: The risk G allele in rs3852942 (G153D) is strongly associated with the development of XFG in the Western Indian population. Genetic screening strategies to identify LOXL1 risk alleles in the population can assist in case definition and early diagnosis, targeting precious resources to high-risk patients.