Retinitis Pigmentosa 60
A number sign (#) is used with this entry because retinitis pigmentosa-60 (RP60) can be caused by heterozygous mutation in the PRPF6 gene (613979) on chromosome 20q13.33.
For a general phenotypic description and a discussion of genetic heterogeneity of retinitis pigmentosa, see 268000.
Clinical FeaturesTanackovic et al. (2011) described the proband from a 4-generation family of European descent segregating autosomal dominant retinitis pigmentosa, who presented at 37 years of age for evaluation of decreased night vision and loss of peripheral vision. Funduscopy revealed bilateral normal discs with atrophy just temporal to the disc, clear macula, attenuated retinal arterioles, and bone spicule pigment all around the periphery. Reexamination almost 20 years later at 55 years of age demonstrated progression of disease, with decline in visual acuity to hand motions OD and 20/100 OS, as well as reductions in visual fields and full-field ERG amplitudes; funduscopy at that time showed waxy pallor of the discs bilaterally, atrophy of the retinal pigment epithelium and prominent choroidal vessels in each macula, attenuated retinal vessels, and bone spicule pigment visible in the midperiphery. An affected brother was diagnosed with RP at 16 years of age when he was evaluated for reduced night vision. He reported loss of peripheral vision at around 40 years of age. Although he was 2 years younger than the proband, his vision was always worse than that of his brother and gradually decreased to light perception only in both eyes by age 54 years.
Molecular GeneticsIn 188 probands from families segregating autosomal dominant retinitis pigmentosa, Tanackovic et al. (2011) screened the candidate gene PRPF6 and identified a heterozygous missense mutation in 1 proband (613979.0001). The mutation was also detected in heterozygosity in his affected brother but was not found in 1,078 ethnically matched control chromosomes. Tanackovic et al. (2011) stated that PRPF6 was the sixth gene involved in pre-mRNA splicing and autosomal dominant RP, corroborating the hypothesis that deficiencies in the spliceosome play an important role in the molecular pathology of the disease.