Analysis of LOXL1 polymorphisms in a Saudi Arabian population with pseudoexfoliation glaucoma

PURPOSE: To investigate whether single nucleotide polymorphisms (SNPs) in the lysyl oxidase-like 1 (LOXL1) gene are associated with pseudoexfoliation glaucoma (PEG) in the Saudi Arabian population. METHODS: The coding regions of LOXL1 were fully sequenced in 93 clinically diagnosed PEG patients and 101 healthy controls. Both groups were Saudi Arabs. Previously reported and newly identified SNPs were evaluated for possible association with PEG and their pathological consequences on the gene were assessed. RESULTS: The “G” allele frequencies of both rs1048661 and rs3825942 SNPs differed between PEG patients and control subjects from Saudi Arabia (p=0.0056 and p=0.000005, respectively). This significance remained after applying the Bonferroni correction. Two non-synonymous novel SNPs in LOXL1 were detected in the PEG patients and not in the controls. One of these SNPs was in exon 4 (g.25722 C>G; codon change D484E) of LOXL1 and was predicted to be non-pathological; the other was in exon 6 of LOXL1 (g.28084 T>G; codon change Y559D) and was predicted to be probably damaging. All alleles of SNPs (rs28706550, rs35203737, rs41429348, rs12906373, rs41435250, and rs13329473) were monoallelic in this population. No allele frequency difference for rs8818 and rs3522 SNP between patients and controls (p values were 0.126 and 0.994 respectively). CONCLUSIONS: Similar to almost all non-African populations tested thus far, the “G” allele of both rs1048661 and rs3825942 SNPs were associated with the risk of PEG in the Saudi Arab population.