Exon-intron structure of a 2.7-kb transcript of the STM7 gene with phosphatidylinositol-4-phosphate 5-kinase activity

The STM7 gene encodes a novel phosphatidylinositol-4-phosphate 5-kinase (PtdInsP B-kinase) that is subject to alternative splicing and developmental control. We have recently presented data indicating that several splice variants of STM7 incorporate elements of the X25 sequence, previously implicated in the pathogenesis of Friedreich's ataxia by the detection of an intronic GAA repeat expansion as the predominant mutation in affected individuals. We now report the exon-intron structure of STM7.1 and primer sequences designed to facilitate full characterization, including details relating to a novel exon (STM7; exon 17) derived from the 3'-UTR of the PRKACG gene. The detection of a mutation(s) within these exons would provide additional support for the hypothesis that a defect in phosphoinositide metabolism gives rise to the disease phenotype. (C) 1997 Academic Press.