Deficiency of 3-hydroxy-3-methylglutaryl-CoA lyase can present
in the newborn with severe hypoketotic hypoglycemia, metabolic acidosis, and hyperammonemia,
or with episodes of hypoglycemia, hepatomegaly, and encephalopathy
following intercurrent infection. The latter form of the disease
is often mistaken for Reye syndrome. If not promptly treated, cerebral
atrophy, neurological effects, and mental retardation may follow.