Abstract
Purpose: :
Keratoconus (KTCN) is a non-inflammatory thinning and anterior protrusion of the cornea that results in steepening and distortion of the cornea, altered refractive powers, and altered visual acuity. We ascertained eighteen autosomal dominant multigenerational KTCN families from Ecuador and identified a novel locus on 13q32.1-q32.3. Here we present sequencing results of candidate keratoconus genes localized to 13q32.
Methods: :
The keratoconus locus contains 23 known transcripts. Twelve of the genes were chosen for the evaluation. Genes are screened by standard techniques using genomic DNA samples from all individuals from family KTCN-014 and selected affected and unaffected individuals from other Ecuadorian families. Coding exons and intron-exon boundaries of the genes are evaluated.
Results: :
Sequencing analysis of genes MBNL2, FARP1, ZIC5, ZIC2, FGF14, EFNB2, and RNF113B have not revealed mutations segregated with the disease phenotype. Several novel single nucleotide polymorphisms were identified. Other candidate genes, including DOCK9, PHGDHL1, VGCNL1, ERCG5, ING1 are currently being screened for a possible role in the pathogenesis of KTCN.
Conclusions: :
To date, mutation analyses of candidate genes have not identified sequence alterations segregating with the keratoconus phenotype in this population.
Keywords: keratoconus • gene screening