Congenital myopathies.

A retrospective review of 55 children with the clinical (pre-biopsy) suspicion of a congenital or metabolic myopathy was undertaken. After investigations, 45% remained unclassified. The only statistically significant differences between this unclassified group and the others were that males with a history of progressive disease were more likely to have a definable myopathy, while 'neuropathic' features were more common in the unclassified group.