Congenital cataracts are caused by gene abnormalities that fall into four major categories: mutations in genes that encode (1) crystallins, (2) lens membrane proteins like connexin and aquaporin, (3) cytoskeletal structural proteins, and (4) other genes, such as ITX3 (paired-like homeodomain 3), PAX6 (paired box 6), HSF-4 (heat shock protein factor 4), and HCR7 (7-dehydrocholesterol reductase).135. The gene discussed is HSF4; the disease is cataract.