Congenital hypotonia revisited.

The definition of neuromuscular diseases affecting infants has depended on factors as various as the rate of progression of the illness, the clinical picture, and, recently, the morphologic peculiarities in the muscle biopsy. A review of the literature suggests that there are discrepancies in the classification of such illnesses, no matter what system is used. In some instances, a single diagnosis seems to include patients with quite separate illnesses, whereas other patients with seemingly identical diseases have been given different diagnoses.