1. an inborn error of metabolism characterized by excessive amounts of methylmalonic acid in the blood and urine, with developmental retardation, hepatomegaly, intermittent neutropenia, thrombocytopenia, and severe metabolic acidosis. It is due to any of various defects causing deficiency of activity of an enzyme necessary for using as fuel isoleucine, threonine, valine, propionic acid, and other fatty acids with odd number chain lengths.
2. excess of methylmalonic acid in the blood.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.