MTM1 and X-linked myotubular myopathy: Necklace fibres with nuclear internalisation have been reported as a histological hallmark of X-linked myotubular myopathy related to mutations in the phosphoinositide phosphatase myotubularin 1 (MTM1) gene and also a late-onset dynamin-2 (DNM2) gene-related centronuclear myopathy [11, 12].