Cataract 19, Multiple Types

A number sign (#) is used with this entry because of evidence that multiple types of cataract (CTRCT19) are caused by homozygous mutation in the LIM2 gene (154045) on chromosome 19q13.

Description

Mutation in the LIM2 gene has been identified in 1 family with cataracts described as late-onset cortical pulverulent and in another family with congenital cataracts described as total.

Clinical Features

Pras et al. (2002) reported an inbred Iraqi Jewish family in which 3 sibs with presenile cataract was first noticed between the ages of 20 and 51 years. The cataracts were described as cortical pulverulent cataracts. They made their presence evident by blurred vision and glare at a mean age of 40 years.

Ponnam et al. (2008) studied a consanguineous Indian family in which 4 affected individuals over 2 generations had congenital cataract. The proband had undergone cataract surgery for 'total cataract' at 3 years of age. At age 6 years, he was pseudophakic in both eyes with dense amblyopia. His visual acuity was 20/200 in the right eye and counting fingers at 1 meter in the left eye. His affected brother was reported to have had total cataract at 2 years of age, and to have undergone surgery at age 4 years. The proband's maternal aunt and uncle also had congenital and developmental cataract, respectively, and underwent cataract removal within the first decade of life. All affected individuals had nystagmus and dense amblyopia.

Mapping

In a consanguineous family segregating late-onset cortical pulverulent cataracts, Pras et al. (2002) used microsatellite repeat markers in close proximity to 25 genes and loci previously associated with congenital cataracts in humans and mice and identified 5 markers on 19q that cosegregated with the disorder.

Molecular Genetics

In affected members of a consanguineous family segregating late-onset cortical pulverulent cataracts mapping to chromosome 19q, Pras et al. (2002) identified a homozygous missense mutation in the LIM2 gene (F105V; 154045.0001).

Ponnam et al. (2008) screened the probands from 40 Indian families with congenital or developmental cataract for mutation in 10 candidate genes and identified 1 family with congenital total cataract in which homozygosity for a missense mutation in the LIM2 gene (G154E; 154045.0002) segregated with disease and was not found in 75 ethnically matched controls.