Detailed Information on Methylmalonic Aciduria

Methylmalonic acidemia (MMA), also called methylmalonic aciduria. Methylmalonic Aciduria is a disorder of amino acid metabolism, involving a defect in the conversion of methylmalonyl-coenzyme A (CoA) to succinyl-CoA. This condition occurs in an estimated 1 in 50,000 to 100,000 people. About 1 in 25,000 - 48,000 babies are born with this condition. Methylmalonic Aciduria affects boys and girls similarly. A severe nutritional deficiency of vitamin B12 can also result in methylmalonic aciduria.

Methylmalonyl CoA requires vitamin B12 to form succinyl-CoA. The effects of methylmalonic acidemia, which usually appear in early infancy, vary from mild to life-threatening. Symptoms of Methylmalonic Aciduria usually begin in the first few months of life. Affected child’s experience vomiting, dehydration, weak muscle tone (hypotonia), excessive tiredness (lethargy), and failure to gain weight and grow at the expected rate (failure to thrive). Babies may appear normal at birth, but develop symptoms once start eating more protein, which can cause the condition to get worse.

Long-term complications can include feeding problems, mental retardation, chronic kidney disease, and inflammation of the pancreas (pancreatitis). Parents or care-givers of a child with a first seizure should instantly seek medical attention. Treatment of Methylmalonic Aciduria includes a carefully controlled diet, including a low-protein regimen and/or restriction of isoleucine, valine, and threonine. A low-protein maintenance diet can help to reduce recurrent attacks of acidemia. Prevention is better than cure. Patients should also avoid people who are sick. Limit protein catabolism during acute metabolic crises.

Stop usual protein intake and intravenously administer generous fluid and glucose if necessary. Carnitine supplement may also be advised for some affected indivuduals. Parents of a child with this disorder or couples desiring children who have a known family history of this disorder should seek information on genetic counseling. Provide calcium and multivitamin supplementation to avoid osteopenia and vitamin deficiency, respectively. Medical food supplementation may be needed. Physical and occupational therapist may help in functionally retraining patients.