Rpgr^Rd9

Sequence analysis identified a 32-bp duplication in the alternatively-spliced exon ORF15. The duplication produces a frame shift in the repetitive region of ORF15 that introduces a premature-stop codon, and is predicted to result in a truncated protein in which the C-terminal 108 amino acids are unrelated to the wild-type protein and are predominantly basic. RT-PCR confirmed expression of both the constitutive variant encoding exons 1-19 and the isoform encoding exons 1-13 and ORF15. However, the ORF15 isoform protein is not detected in immunoblot of retinal extracts or connecting cilia, while wild-type levels of the constitutive isoform Rpgr 1-19 are present in retinal lysates and are decreased in photoreceptor cells. (J:237833)