Myotubular myopathy [also called X-linked centronuclear myopathy (CNM), XLCNM, XLMTM; OMIM 310400] is due to mutations in the phosphoinositide phosphatase myotubularin (MTM1) (Laporte et al., 1996). This evidence concerns the gene MTM1 and X-linked myotubular myopathy.