Rivolta et al. (2002) described a patient with isolated RP who had complete paternal heterodisomy for chromosome 1. Clinical findings were typical, including fundi with attenuated retinal vessels and intraretinal bone spicule pigment around the periphery. Electroretinograms (ERGs) ... Rivolta et al. (2002) described a patient with isolated RP who had complete paternal heterodisomy for chromosome 1. Clinical findings were typical, including fundi with attenuated retinal vessels and intraretinal bone spicule pigment around the periphery. Electroretinograms (ERGs) were reduced but detectable at the age of 54 years. This patient had been part of the study of Rivolta et al. (2000). Kaiserman et al. (2007) studied a large Iraqi Jewish family with a complex pattern of inheritance in which some family members suffered from Usher syndrome type 2 while others had nonsyndromic RP. At the age of 66 years, the mother in the nuclear family had advanced RP with nonrecordable ERG responses and severely constricted visual fields. Her 3 daughters with RP (aged 32 to 39 years) had somewhat less severe retinal disease, but all were legally blind.
The patient described by Rivolta et al. (2000) and Rivolta et al. (2002) with RP and homozygosity for a cys759-to-phe mutation in the USH2A gene (608400.0006) was determined to be completely paternally heterodisomic for chromosome 1 with isodisomic ... The patient described by Rivolta et al. (2000) and Rivolta et al. (2002) with RP and homozygosity for a cys759-to-phe mutation in the USH2A gene (608400.0006) was determined to be completely paternally heterodisomic for chromosome 1 with isodisomic segments at the distal ends of the long and short arms. In the large Iraqi Jewish family studied by Kaiserman et al. (2007), 3 different mutations in the USH2A gene caused 2 phenotypes. Two of the mutations were null (2139insCGAT, 608400.0010 and R737X, 608400.0011) and were found in affected individuals with either Usher syndrome or RP; a novel missense mutation (R4674G; 608400.0012) was specific to the RP phenotype.