Mutations and mechanisms in congenital and age-related cataracts

Abstract

The crystalline lens plays an important role in the refractive vision of vertebrates by facilitating variable fine focusing of light onto the retina. Loss of lens transparency, or cataract, is a frequently acquired cause of visual impairment in adults and may also present during childhood. Genetic studies have identified mutations in over 30 causative genes for congenital or other early-onset forms of cataract as well as several gene variants associated with age-related cataract. However, the pathogenic mechanisms resulting from genetic determinants of cataract are only just beginning to be understood. Here, we briefly summarize current concepts pointing to differences in the molecular mechanisms underlying congenital and age-related forms of cataract.

Keywords: Cataract; Crystallin; Genetic; Lens; UPR.

Fig. 1

Possible genetic pathways leading to cataracts. Severe mutations would be more likely to cause highly penetrant Mendelian congenital cataracts, while mild changes would be likely to increase susceptibility to environmental insults and lead to multifactorial age-related cataracts. Black arrows show demonstrated pathways and gray arrows show likely pathways.