Nonspecific congenital myopathy (minimal change myopathy): a case report.

A 28-month-old male with generalized hypotonia and muscle weakness, a myopathic face, skeletal dysmorphism and delayed motor milestones from birth is reported. He gradually developed the ability of sitting and rolling over, but could not stand without support until 28 months. There was no intellectual impairment or seizures. Deep tendon reflexes were absent. The serum CK value, peripheral nerve conduction velocity and EMG were within normal limits. A muscle biopsy specimen showed mild variation in fiber size, and an increased number of type 2C fibers on histochemical examination, but no apparent abnormalities on electron microscopy. The baby was tentatively diagnosed as having minimal change myopathy or nonspecific congenital myopathy which is thought to be one of the congenital nonprogressive myopathies.