Analysis of VSX1, HGF and LOX in the Pakistani familial and sporadic Keratoconus patients

Purpose: Three genes VSX1, HGF and LOX have been previously reported to be causative of keratoconus (KC) in different populations. In the current study we investigated the role of these genes in three autosomal recessive Pakistani families and 100 sporadic KC cases from Pakistan. Methods: Mutation analysis of VSX1 gene was done by Sanger sequencing of three KC families, while 100 sporadic cases including 10 cases with positive maternal family history were sequenced for mutation hotspot exon 2 of the gene. For the sporadic cases, case-control association analysis was also performed for KC associated reported polymorphisms in HGF (rs17501108 and rs3735520), and LOX (rs1800449, rs2288393 and rs2956540) gene through polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results: Screening of the VSX1 did not reveal any mutation in KC panel, a synonymous polymorphism rs12480307 (c.546A>G; p.Ala182Ala) in exon 3 was observed in one of the proband who inherited it homozyogusly from the carrier parent. This polymorphism was not observed in sporadic KC cases. In addition no significant association of the HGF and LOX SNPs were observed through case-control association analysis of sporadic cases. Conclusion: This is the first report of KC genetics from Pakistan where we excluded the role of VSX1 in Pakistani KC panel, in addition none of the previously reported SNPs of HGF and LOX have any involvement in disease pathogenesis in Pakistani KC cases.