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-kinas e (PtdInsP B-kinase) that is subject to alternative splicing and devel opmental control. We have recently presented data indicating that seve ral splice variants of STM7 incorporate elements of the X25 sequence, previously implicated in the pathogenesis of Friedreich's ataxia by th e detection of an intronic GAA repeat expansion as the predominant mut ation in affected individuals. We now report the exon-intron structure of STM7.1 and primer sequences designed to facilitate full characteri zation, including details relating to a novel exon (STM7; exon 17) der ived from the 3'-UTR of the PRKACG gene. The detection of a mutation(s ) within these exons would provide additional support for the hypothes is that a defect in phosphoinositide metabolism gives rise to the dise ase phenotype. (C) 1997 Academic Press.