Case 6 History ---- The patient was a 22 month old girl who was born at term. She developed normally until the age of six months when developmental and growth arrest were noted accompanied by wandering eye movements and ptosis. By 12 months, she was below the fifth percentile in height, weight, and head circumference; by 16 months, she had lost previously acquired milestones. Audiometry testing indicated moderate bilateral hearing loss. Karyotype was performed and interpreted as 46,XX. A serum amino acid screen showed an increased alanine level. Evaluation at Children's Hospital in Boston included blood levels of arylsulfatase. galactocerebrosidase, galactosidase, long chain fatty acids, and phytanic acid; all results added no further diagnostic information. A TI and T2 weighted MRl at 21 months showed increased signal of the thalamus (bilateral), pons and midbrain with decreased differentiation between grey and white matter. Physical examination revealed a lethargic child with symmetrically decreased muscle tone throughout. Elevated serum levels of pyruvate, lactate, and alanine, and elevated CSF levels of pyruvate and lactate, were noted. Serum ammonia was normal. EMG and nerve conduction velocities were unremarkable. She was readmitted following two weeks of decreased tone and decreased responsiveness to verbal and tactile stimuli. On the day before admission, she developed fever, loose black stools, and vomiting. On the morning of admission, her parents found her lying in vomitus, unresponsive, and with cold, blue extremities. Resuscitation efforts included intubation and pressor support, but she developed decerebrate posturing with loss of pupillary and corneal reflexes. Although pupillary reflexes returned within 24 hours, respirator support was withdrawn in consideration of her generally poor prognosis.
