Intermittent hypermethioninaemia associated with normal hepatic methionine adenosyltransferase activity: report of a case.

A 5-month-old infant was found to have hypermethioninaemia (0.8 mumol/ml) that has persisted intermittently (0.02-1.3 mumol/ml) over a period of 3 years. She presented with developmental delay and failure to thrive associated with gross abuse and neglect. Histological examination of the liver revealed inflammation of the portal triads. The activity of hepatic L-methionine-S-adenosyltransferase (EC 2.5.1.6) was normal. Whether the biochemical findings were the cause or the result of the hepatic damage is uncertain, but the minimal histological findings in the liver suggest a primary biochemical defect.