Abstract
Purpose:
Mutations in the pre-mRNA splicing gene SNRNP200 have been identified as a cause of autosomal dominant retinitis pigmentosa (adRP). In order to determine the prevalence of SNRNP200 mutations, a cohort of well characterized adRP patients was screened.
Methods:
A cohort of 258 probands has been systematically screened for mutations in the genes currently known to cause adRP. Of these 258 individuals, mutations have been identified in 185, leaving a set of 73 with no known disease-causing mutation. All 45 exons of SNRNP200 were screened by fluorescent di-deoxy sequencing in this subset of the adRP cohort. Identified variants were tested for segregation in additional family members when available.
Results:
In the set of 73 adRP patients screened, six were found to have missense mutations in SNRNP200. Three families have a previously identified change (Arg681His) while the other three were found to have novel variants (Ala542Val, Pro682Ser, Gly1162Glu). The Ala542Val mutation was found in two additional affected family members. All three novel variants are predicted to be pathogenic and are not found in databases of normal controls.
Conclusions:
A comprehensive screen of the SNRNP200 gene has identified likely disease-causing mutations in 6 of 73 individuals tested. The overall prevalence of SNRNP200 mutations in our adRP cohort is 2.3% (6/258). This further confirms the role of proteins in the U4/U6-U5 tri-snRNP splice complex, including PRPF3, PRPF8, PRPF31 and SNRNP200, in adRP.
Keywords: 696 retinal degenerations: hereditary •
537 gene screening •
604 mutations