2020–2021 BCSC Basic and Clinical Science Course™
11 Lens and Cataract
Chapter 4: Embryology and Developmental Defects
Genetic Contributions to Age-Related Cataracts
Studies of identical and fraternal twins and of familial associations suggest that a large proportion of the risk of age-related cataracts is inherited. It is estimated that inheritance accounts for more than 50% of the risk of cortical cataracts. Studies have identified mutations in the gene associated with congenital and age-related cortical cataracts, EPHA2, which has been mapped to 1p36. This is the first gene known to cause hereditary, nonsyndromic age-related cortical cataracts, although mutations at this locus account for only a small fraction of cortical opacities. Similarly, 35%–50% of the risk of nuclear cataracts can be traced to inheritance. Identification of the genes associated with increased risk of cortical and nuclear cataracts is important, because understanding the biochemical pathways in which they function may suggest ways to slow the progression or prevent the development of age-related cataracts in a large number of cases.
Jun G, Guo H, Klein BE, et al. EPHA2 is associated with age-related cortical cataract in mice and humans. PLoS Genet. 2009;5(7):e1000584.
Shiels A, Bennett TM, Knopf HL, et al. The EPHA2 gene is associated with cataracts linked to chromosome 1p. Mol Vis. 2008;14:2042–2055.
Excerpted from BCSC 2020-2021 series: Section 11 - Lens and Cataract. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.