Cataract 38

A number sign (#) is used with this entry because of evidence that autosomal recessive cataract-38 (CTRCT38) is caused by homozygous mutation in the AGK gene (610345) on chromosome 7q34.

See also Sengers syndrome (212350), a syndromic form of congenital cataract caused by mutation in AGK.

Clinical Features

Aldahmesh et al. (2012) reported a sister and 2 brothers from a consanguineous Saudi family who were born with congenital cataract but had otherwise normal ophthalmologic and systemic examinations. Specifically, cardiac evaluation including electrocardiography and echocardiography showed no evidence of structural or functional impairment, they had normal muscle power clinically and lacked any history of exercise intolerance, and lactic acid was normal in all 3 patients.

Mapping

In a consanguineous family segregating autosomal recessive congenital cataract, Aldahmesh et al. (2012) performed linkage analysis and obtained a single peak with a lod score of 3.1 (rs6962852), delimited by recombinations at rs12668057 and rs4726235. Autozygosity mapping both confirmed and narrowed the critical region on 7q to an interval between rs11765427 and rs10278502.

Inheritance

The transmission pattern of cataract in the family reported by Aldahmesh et al. (2012) was consistent with autosomal recessive inheritance.

Molecular Genetics

In a consanguineous Saudi family with nonsyndromic congenital cataract mapping to chromosome 7q33-q36.1, Aldahmesh et al. (2012) performed exome sequencing and identified a homozygous splice site mutation in the AGK gene (610345.0010) that segregated with disease.