Keratoconus (KC) is the most common form of keratoectasia characterized by changes in corneal
topography and its thinning, stretching, and protrusion. The hereditary or genetic theory of keratoconus
development is widely recognized. To date, a large number of candidate genes have been investigated in
patients with KC. One of the most important of them are the gene encoding a homeodomain-containing protein
that belongs to the subfamily of paired-like homeodomain proteins (VSX1), superoxidedismutase 1
(SOD1) gene, and the gene of lysyloxidase (LOX). The linkage analysis reveals over 17 chromosomal regions
mutations in which can lead to the development of KC. In families with a hereditary form of keratoconus by
GWAS analysis, the association of central corneal thickness (CCT) with a number of genetic loci is revealed.
Thus, diverse results of genetic studies and a large number of identified chromosomal regions associated with
keratoconus, firstly, show marked genetic heterogeneity of the disease and, secondly, are associated with
challenges in DNA diagnosis of this disease. However, there are prerequisites that keratoconus belongs to
both hereditary and genetically caused diseases and identified genetic variants are specific both to individual
populations and to certain ethnic groups in general.