Case 2 History ---- This male infant was first seen at St. Louis Children's Hospital at the age of 14 months to evaluate vomiting of unknown cause, regression of developmental milestones and nystagmus. The child had mild respiratory distress syndrome at birth (born 37 weeks). His height and weight increased at the 3rd percentile and his head circumference at the 25th percentile; however his neurologic development appeared to progress normally. At 1 year of age he began repetitive vomiting and was hospitalized several times without diagnosis. Thereafter, he lost weight and motor capabilities regressed. He exhibited bilateral, horizontal nystagmus. A neurology consultant thought that he had a progressive neurologic disorder, favoring Leigh's disease as first choice or leukodystrophy, particularly metachromatic or Krabbe disease, as a second choice. On the 7th hospital day he developed Kussmaul respirations and serum electrolytes showed a serum bicarbonate of 9 mEq/1, pCO2 of 19, pO2 of 111 and arterial pH of 7.39. He became comatose. After an extensive and exhaustive workup, it was thought that the child had metabolic acidosis and, again, Leigh’s disease was thought most likely. There were a few plaque-like areas of white matter lucency in the centrum semiovale which supported that diagnosis. He continued to have ataxic eye movements, fisting and flexion of the upper extremities when excited or upset. He manifested increased tone in his lower extremities with ankle clonus. Bilateral vocal cord paresis continued combined with failure to thrive, developmental delay and regression. The patient expired two weeks later at the age of 17 months.
