Mutations in the CRYAB gene have been found to cause multiple types of cataract, which have been described as congenital posterior polar, congenital lamellar, and juvenile. Autosomal dominant and autosomal recessive forms have been described.
The ... Mutations in the CRYAB gene have been found to cause multiple types of cataract, which have been described as congenital posterior polar, congenital lamellar, and juvenile. Autosomal dominant and autosomal recessive forms have been described. The preferred title/symbol of this entry was formerly 'Cataract, Posterior Polar, 2; CTPP2.'
Berry et al. (2001) reported a 4-generation family of English descent with autosomal dominant posterior polar cataract. The opacity was bilateral in all cases and consisted of a single well-defined plaque confined to the posterior pole of the ... Berry et al. (2001) reported a 4-generation family of English descent with autosomal dominant posterior polar cataract. The opacity was bilateral in all cases and consisted of a single well-defined plaque confined to the posterior pole of the lens and that was 0.5 to 3 mm in diameter. It was present at birth or developed during the first few months of life but did not progress with age to other regions of the lens. There was no evidence of posterior lenticonus or high myopia, and there was no family history of other ocular or systemic abnormalities. Liu et al. (2006) examined 4 affected and 5 unaffected members of a large 5-generation Chinese family segregating autosomal dominant congenital cataract. All affected individuals displayed bilateral lamellar cataracts of variable severity, with no other ocular or systemic abnormalities. Slit-lamp examination of the proband showed lens opacification that was restricted to discrete lamellae and the inner embryonic nucleus, whereas the surrounding cortex remained clear. Liu et al. (2006) studied 13 affected and 8 unaffected members of a 4-generation Chinese family segregating autosomal dominant bilateral posterior polar cataract. Vision began to deteriorate at a young age in all affected individuals and progressed to a single well-defined plaque confined to the posterior pole of the lens, with a diameter of 0.6 to 3 mm by the age of 6 to 8 years. All patients required cataract surgery with intraocular lens implantation before the age of 10 years. There were no other ocular defects or cardiovascular or muscular findings, even in the oldest patient, who was 65 years old. Safieh et al. (2009) examined 5 affected (a mother and 4 children) and 4 unaffected members of a 2-generation consanguineous Saudi family with cataract. The 35-year-old mother, who underwent cataract surgery within the first 6 months of life, had bilateral aphakia and retinal dystrophic changes; electroretinography (ERG) confirmed depressed retinal function, both scotopic and photopic. Her 16-year-old daughter had bilateral cataract surgery at 16 months of age for visually significant cataracts that were described as dense, complete, and white; examination showed aphakia and total retinal detachment on the right and was unremarkable on the left. A 14-year-old daughter underwent extraction of visually significant nuclear cataracts at 6 years of age; examination revealed bilateral aphakia but was otherwise unremarkable. Five younger sibs had no ophthalmic complaints, but examination revealed that 2 of them had clinically insignificant opacities: a 6-year-old girl had nuclear and cortical opacities on slit-lamp examination, and a 1-year-old boy had fine opacities in the red reflex on retinoscopy. The father had a normal ophthalmologic examination.
In a 4-generation family of English descent with autosomal dominant congenital posterior polar cataracts, Berry et al. (2001) identified heterozygosity for a deletion mutation in the CRYAB gene (123590.0002). Berry et al. (2001) suggested that the cataract in ... In a 4-generation family of English descent with autosomal dominant congenital posterior polar cataracts, Berry et al. (2001) identified heterozygosity for a deletion mutation in the CRYAB gene (123590.0002). Berry et al. (2001) suggested that the cataract in this family resulted from an increased tendency of the mutant polypeptide to aggregate and/or from loss of chaperone-like activity. In affected members of a large 5-generation Chinese family with congenital lamellar cataract, who were negative for mutation at known hotspots in 9 cataract-associated genes, Liu et al. (2006) identified heterozygosity for a missense mutation in CRYAB (D140N; 123590.0008) that segregated with disease and was not found in 100 controls. In a 4-generation Chinese family with congenital posterior polar cataract mapping to 11q22, Liu et al. (2006) identified a heterozygous missense mutation in the CRYAB gene (P20S; 123590.0009) that segregated fully with disease in the family and was not found in 200 controls. In an affected mother and 4 affected children from a consanguineous Saudi family with cataract mapping to 11q21-q23, Safieh et al. (2009) identified homozygosity for a missense mutation in the CRYAB gene (R56W; 1234590.0010). The unaffected father was heterozygous for the mutation, which was not found in 150 Saudi controls.