Maw et al. (2000) reported a consanguineous Indian family in which 4 of 8 sibs had night blindness and loss of peripheral vision from childhood with progression to profound visual impairment and extinguished electroretinograms (ERG) by their third ... Maw et al. (2000) reported a consanguineous Indian family in which 4 of 8 sibs had night blindness and loss of peripheral vision from childhood with progression to profound visual impairment and extinguished electroretinograms (ERG) by their third decade. Fundus examination revealed narrowed arteries, optic disc pallor, pigment deposits, and macular degeneration. One sister also had polydactyly on one foot. Polydactyly and retinal degeneration are manifestations of Bardet-Biedl syndrome (see 209900); however, the authors stated that none of the other manifestations of that disorder were present in this family. Zhang et al. (2007) described a consanguineous Pakistani family with a severe form of retinitis pigmentosa accompanied by macular degeneration. Rod and cone responses on ERG were extinguished in the second decade. Fundus examination revealed waxy-pale discs, obvious attenuation of the retinal arteries, macular degeneration, and typical bone-spicule pigmentation in the midperipheral retina in all 6 affected individuals. Atrophy of the choriocapillaris and posterior retinal pigment epithelium allowed visualization of the large choroidal vessels in patients over age 40 years. None of the affected individuals had polydactyly or other systemic abnormalities.
In affected members of a consanguineous Indian family with retinal degeneration, Maw et al. (2000) identified homozygosity for a 1-bp deletion in the PROM1 gene (604365.0001), predicted to cause truncation of the protein. The mutation was not found ... In affected members of a consanguineous Indian family with retinal degeneration, Maw et al. (2000) identified homozygosity for a 1-bp deletion in the PROM1 gene (604365.0001), predicted to cause truncation of the protein. The mutation was not found in 97 Indian controls. In all 6 affected members of a consanguineous Pakistani family with severe retinitis pigmentosa, Zhang et al. (2007) identified homozygosity for a nonsense mutation in the PROM1 gene (604365.0002). Five of 6 unaffected family members were heterozygous for the mutation, which was not found in 192 ethnically matched unrelated controls from the same region.