Centronuclear myopathy with cataracts due to a novel dynamin 2 (DNM2) mutation

Dynamin 2 (DNM2)-related dominant centronuclear myopathy is usually a mild disorder, but more severe variants have been associated with mutations affecting the pleckstrin homology (PH) domain of the protein, mainly implicated in different forms of Charcot-Marie-Tooth Disease (CMT). Whilst DNM2-related CMT may feature non-neurological findings including cataracts, this has not been reported in DNM2-related centronuclear myopathy. We report a girl presenting from birth with hypotonia, respiratory and feeding difficulties. Motor development was delayed and at 9 years she lost the ability to walk. She had ptosis, external ophthalmoplegia and bilateral cataracts. Muscle biopsy showed increase in central nuclei with type 1 hypotrophy and fibrosis. DNM2 screening revealed a novel heterozygous substitution (c.1862T>C; p.Leu621Pro) affecting the PH domain of the protein. Her further course was progressive and at 14 years she died from respiratory failure. Our findings expand the phenotypical spectrum associated with DNM2 mutations and provide a new clinical indicator for involvement of this gene in patients with centronuclear myopathy.