In the population of Spain, 39% of the retinitis pigmentosa pedigrees show an autosomal recessive pattern of inheritance (Ayuso et al., 1995). Martinez-Mir et al. (1997) described a consanguineous Spanish family in which 6 of 7 sibs were ... In the population of Spain, 39% of the retinitis pigmentosa pedigrees show an autosomal recessive pattern of inheritance (Ayuso et al., 1995). Martinez-Mir et al. (1997) described a consanguineous Spanish family in which 6 of 7 sibs were affected. The parents, who were related as second cousins, were unaffected. The mean age of onset was 8 years. Night blindness was followed by a decrease in visual acuity, starting at 14 years of age. Fundus examination showed papillary pallor, attenuated vessels, peripheral scattered pigmentation, bone spicule-like pigmentation reaching some areas of the macula, and severe atrophy of the retinal pigment epithelium.
Since RP19 maps to the same region of the short arm of chromosome 1 as the Stargardt disease locus, Martinez-Mir et al. (1998) sought mutations in the ABCR gene, which is mutant in Stargardt disease. They identified a ... Since RP19 maps to the same region of the short arm of chromosome 1 as the Stargardt disease locus, Martinez-Mir et al. (1998) sought mutations in the ABCR gene, which is mutant in Stargardt disease. They identified a 1847delA frameshift mutation in the ABCR gene (610691.0008) in a consanguineous Spanish family that showed linkage to 1p. In a family segregating RP19 and STGD1 in 2 first cousins, Rozet et al. (1999) found that heterozygosity for a splice acceptor site mutation in the ABCR gene (601691.0017) resulted in STGD1, whereas hemizygosity for this mutation resulted in RP19. In the patient with RP19, a partial deletion of the maternal ABCR gene was presumed to be the source of a null allele, although this was not conclusively proven.