A 15-bp deletion in exon 5 of the ornithine aminotransferase (OAT) locus associated with gyrate atrophy

✍ Scribed by James K. Park; James J. O'Donnell; Vivian E. Shih; James F. Gusella; Vijaya Ramesh

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 511 KB
• Volume: 1
• Category: Article
• ISSN: 1059-7794
• DOI: 10.1002/humu.1380010405

✦ Synopsis

Communicated by David W. Yandell Gyrate atrophy of the choroid and retina (GA) is an autosomal recessive disorder in which a deficiency of the mitochondrial matrix enzyme ornithine aminotransferase (OAT) leads to progressive blindness. Previously, we and others have reported a number of missense mutations and splice defects in the O A T gene associated with GA. In the present case, through sequencing of the PCR amplified cDNA products, we have detected a novel 15-bp deletion within exon 5 of the O A T gene which retains the original reading frame. The deleted PCR product is the only one produced from the patient's mRNA, while mRNA from the patient's mother yields both deleted and normal length PCR products. The alternate, apparently nonexpressing OAT allele in this patient was inherited from the father, who displays only the normal length PCR product. The codon at the deletion joint remains unaltered, predicting the loss of the pentapeptide Tyr-Thr-Val-Lys-Gly without any other amino acid change. The breakpoints are adjacent to or within two copies of a 4-bp direct repeat, which may have implications for the mechanism of deletion. o 1992 WiIey-Liss, Inc.