Genetics of keratoconus

Keratoconus (KC) is the most common corneal ectatic disorder. Patients with KC suffer from a significant visual impairment, which in advanced cases can only be restored by corneal transplantation surgery. KC is a complex disorder attributed to different contributors including genetics and environmental factors. In this chapter, we aim to report the genetic etiology of KC. Family-based linkage analysis, case-control-based genome-wide association analysis (GWAS), and direct candidate gene sequencing have been used to identify the genetic mutations or risk factors. Linkage analyses have identified multiple genomic loci with chr5q21.2 as the only independently replicated locus. GWAS and candidate gene analyses have identified many KC-associated sequence variants, opening new areas of KC-related research. We expect that more genetic factors will be identified and characterized for KC with the development of novel technologies in genetics.