Abstract
Purpose: :
To investigate the possible genetic association of lysyl oxidase-like 1 (LOXL1) gene, tumor necrosis factor alpha (TNF-α) gene and clusterin (CLU) gene polymorphisms with exfoliation syndrome (XFS) and exfoliation glaucoma (XFG) in South Indian population.
Methods: :
We performed a case-control association study using 300 unrelated cases (150 patients with XFS and 150 patients with XFG) and 225 unrelated age-matched controls from South Indian cohorts. The three LOXL1 single-nucleotide polymorphisms (SNPs), two coding SNPs (rs1048661:R141L and rs3825942: G153D) and one non-coding SNP (rs2165241) were genotyped in all study subjects by direct sequencing and were further confirmed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. Promoter region and all the 7 coding exons with intron-exon junctions of the LOXL1 gene were directly sequenced in 50 affected cases and 50 controls. Single SNP at promoter region in the TNF-α gene (rs1800629, G-308A) was genotyped in 50 patients and 50 healthy controls by using PCR-RFLP approach. Five SNPs in CLU (rs3087554, rs2279590, rs9331931, rs11136000 and rs9331888) were also genotyped using TaqMan SNP assays. All the LOXL1,TNF-α and CLU SNPs were assessed for association with XFS and XFG.
Results: :
Strong association with the three LOXL1 SNPs was seen in both XFS (rs3825942, P = 6.22 x 10-21; rs1048661, P = 6.55 x 10-3; and rs2165241, P = 2.33 x 10-12) as well as in XFG (rs3825942, P = 3.33 x 10-15; rs1048661, P = 5.27 x 10-5; and rs2165241, P = 5.30 x 10-11) cases. No significant difference was detected in the distribution of the five SNPs of CLU between XFS/XFG cases and the general-population controls. Results of TNF-α and CLU SNPs will be discussed.
Conclusions: :
Our results suggest that all the three genetic variants in LOXL1 are associated with XFS/XFG in South Indian population. To the best of our knowledge, we proved using the large sample size, all the three LOXL1 variants are positive for both XFS/XFG in Indian population
Keywords: gene screening • genetics • gene transfer/gene therapy