GENOMIC ORGANIZATION OF THE MTM1 GENE IMPLICATED IN X-LINKED MYOTUBULAR MYOPATHY

X-linked recessive myotubular myopathy (XLMTM) is a very severe congen ital muscular disease characterised by an impaired maturation of muscl e fibres, and caused by defects in the MTM1 gene, This gene defines a new family of putative tyrosine phosphatases conserved through evoluti on. We have determined intronic flanking sequences for all the 15 exon s to facilitate the detection of mutations in patients and genetic cou nselling, We characterised a new polymorphic marker in the immediate v icinity of the gene, which might prove useful for linkage analysis, Se quencing of the TATA-less predicted promoter provides the basis for tr anscriptional regulatory studies.