Analysis of locus 2q13 in Ecuadorian family with keratoconus

Abstract

AbstractPurpose Keratoconus (KTCN) is described as a non‐inflammatory thinning and anterior protrusion of the central cornea which results in altered refractive powers, and loss of visual acuity. The etiology of KTCN remains unknown. Both genetic and environmental factors are associated with the disorder. The purpose of this study was to identify novel genetic factors involved in familial form of KTCN by extensive analysis of multigenerational Ecuadorian family.Methods A total of 22 individuals from KTCN‐019 family were included into this study. Genomic DNA samples of all members of KTCN‐019 family were genotyped with highly polymorphic microsatellite markers. After linkage was established, two positional and functional candidate genes, IL1A and IL1B, were examined with polymerase chain reaction amplification, and direct sequencing of all exons, and intron‐exon boundaries was performed.Results The disease susceptibility locus was mapped on 2q13 chromosome in KTCN‐019 family. Sequencing analysis of the candidate genes, IL1A and IL1B have revealed numerous alterations in coding and non‐coding sequences of both genes including several novel single nucleotide polymorphisms. No mutations segregated with KTCN phenotype have been identified.Conclusion Analysis of IL1A and IL1B genes revealed no mutations segregating with affected phenotype in large Ecuadorian family, indicating that other genes are involved in KTCN causation in this family.