Sibling cases of a degenerative neurological disease associated with hypocupraemia and hypobetalipoproteinaemia.

We describe two siblings, a boy and his younger sister, with degenerative neurological disturbances, hypocupraemia and hypobetalipoproteinaemia. The neurological features in both cases were developmental delay, dysarthria, hyperkinetics with an attention deficit, dysdiadochokinesis, night blindness, myoclonic jerks and convulsions. Their serum cooper levels did not increase despite administration of copper sulphate both orally or intravenously. The copper contents of the cultured fibroblasts in the patients were 1.5-fold that of controls. Although neurological disorders associated with abnormal copper metabolism and inherited in an X-linked manner have been previously reported, this is the first report of a neurodegenerative disease concurrent with abnormal copper metabolism and hypobetalipoproteinaemia.