Congenital fiber type disproportion: a rare type of congenital myopathy: a report of four cases.

Congenital fiber type disproportion is a rare type of congenital myopathy which presents as hypotonia, delayed motor milestones and dysmorphic facies. During the past 2 years we received 449 muscle biopsies, of which 4 cases were diagnosed as congenital fiber type disproportion (CFTD). In addition to CFTD, one case also had centronuclear features. Three of them were females and one was a male child. Although rare, it should be considered in the differential diagnosis of childhood muscle diseases. Histochemical staining is necessary for the diagnosis of this entity.