CRYBB2 and cataract: Mutations in each of these genes lead to several forms of cataract; however, there is no genotype–phenotype correlation possible beside the association between the onset of the crystallin expression in the lens and the age of onset of the disease: cataracts caused by mutations in Cryg genes are visible at weaning (for a review see Graw 2009), but mutations in the Crybb2 gene lead to a progressive cataract starting a few weeks after birth (Kador et al. 1980; Ganguly et al. 2008).