II. Epidemiology

  1. Incidence: 1:20,000
  2. Autosomal Recessive inheritance

III. Pathophysiology

  1. Organic Aciduria

IV. Causes

  1. Most common genetic causes
    1. Methyl-malonyl-CoA mutase defect
    2. Cobalamin synthesis defect
  2. Acquired causes
    1. Pernicious Anemia

V. Signs

  1. Metabolic Ketoacidosis
  2. Encephalopathy
  3. hyperammonemia

VI. Labs

  1. Urine organic acids
  2. Enzyme assay of skin fibroblasts

VII. Management

  1. Acute
    1. Sodium Bicarbonate
    2. Carnitine
  2. Chronic maintenance
    1. Protein restriction
    2. Methylmalonate precursor restriction
    3. Vitamin B12 Supplementation

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Ontology: Methylmalonic acidemia (C0268583)

Definition (NCI) A rare autosomal recessive inherited disorder caused by mutations of the MUT, MMAA, MMAB, MMADHC, and MCEE genes. It is characterized by abnormalities in the metabolism of lipids and proteins. Signs and symptoms usually appear early in life and vary from mild to life threatening. They include vomiting, dehydration, hypotonia, developmental delays, hepatomegaly, lethargy, intellectual disabilities, and chronic kidney disease.
Definition (CSP) autosomal recessive aminoacidopathy characterized by an excess of methylmalonic acid in the blood and urine, with metabolic ketoacidosis, hyperglycinemia, hyperglycinuria and hyperammonemia; results from defects that cause deficiencies of methylmalonyl-CoA mutase.
Concepts Disease or Syndrome (T047)
MSH C537358
ICD10 E71.120
SnomedCT 190727006, 42393006
LNC LP56992-8
English Methylmalonic aciduria, methylmalonic aciduria, methylmalonic acidemia (diagnosis), methylmalonic aciduria (diagnosis), methylmalonic acidemia, Methylmalonic acidemias, Acidemia, methylmalonic, Methylmalonic acidemia, methylmalonic acidaemia, acidemias methylmalonic, Methylmalonic Acidemia, Methylmalonic Aciduria, Isolated Methylmalonic Acidemia, MMA - Methylmalonic aciduria, Methylmalonic acidaemia, Methylmalonic acidemia (disorder), disorder; methylmalonic acidemia, acidemia; methylmalonic, methylmalonic acidemia; disorder, methylmalonic; acidemia, Methylmalonic acidemia, NOS
Italian Aciduria metilmalonica
Japanese メチルマロン酸尿症, メチルマロンサンニョウショウ
Czech Methylmalonová acidurie
Hungarian Methylmalonil aciduria
Dutch acidemie; methylmalon, methylmalon; acidemie, methylmalonacidemie; stoornis, stoornis; methylmalonacidemie, methylmalonzuur acidurie
Spanish acidemia metilmalónica (trastorno), acidemia metilmalónica, Aciduria metilmalónica
Portuguese Acidúria metilmalónica
French Acidurie méthylmalonique
German Methylmalonazidurie