Definition A group of inherited metabolic disorders that cause the accumulation of methylmalonic acid in the body and episodes of severe acidosis and ketosis that can be fatal. Causes, Incidence and Risk Factors Defects in the metabolic pathways of methylmalonic acid , succinic acid, and vitamin B12 activity are responsible for the bouts of acidosis and ketosis. Infection or high protein intake may precede episodes of acidosis.
Untreated acidosis progresses to coma followed by death.
Signs And Tests Physical examination and laboratory testing shows signs of acidosis , ketosis, and elevated serum ammonia . Large doses of vitamin B12 may be given during acute attacks. A low-protein diet must be maintained. Affected infants may not survive their first attack. Recurrent attacks of acidosis are expected.