Congenital fiber type disproportion: Severe form with marked improvement

A 30-month-old male exhibited marked hypotonia at birth accompanied by resp iratory distress necessitating ventilator support. He subsequently demonstr ated marked improvement in muscle power. He became independent of the respi rator at 21 days of age and was able to sit without support at 11 months an d walked alone at 24 months. Histopathologic analysis of the quadriceps fem oris muscle confirmed the diagnosis of congenital fiber type of disproporti on at 11 months of age. No other studies have described a patient with a se vere neonatal form of congenital fiber type of disproportion who demonstrat ed such clear improvement. Physicians should be aware of this possibility w hen they interact with such patients and their families. (C) 1999 by Elsevi er Science Inc. All rights reserved.