MUTATIONS IN THE PDE6B GENE IN AUTOSOMAL RECESSIVE RETINITIS-PIGMENTOSA

We have studied 24 small families with presumed autosomal recessive in heritance of retinitis pigmentosa by a combination of haplotype analys is and exon screening. Initial analysis of the families was made with a dinucleotide repeat polymorphism adjacent to the gene for rod cGMP-p hosphodiesterase (PDE6B). This was followed by denaturing gradient gel electrophoresis (DGGE) and single-strand conformation polymorphism el ectrophoresis (SSCPE) of the 22 exons and a portion of the 5' untransl ated region of the PDE6B gene in the probands of each family in which the PDE6B locus could not be ruled out from segregating with disease. Two probands were found with compound heterozygous mutations: Gly576As p and His620(1-bp del) mutations were present in one proband, and a Ly s706X null mutation and an AG to AT splice acceptor site mutation in i ntron 2 were present in the other. Only the affecteds of each of the t wo families carried both corresponding mutations. (C) 1995 Academic Pr ess, Inc.