Orphanet: Methylmalonic acidemia with homocystinuria

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Methylmalonic acidemia with homocystinuria

Disease definition

A rare inborn error of vitamin B12 (cobalamin) metabolism characterized by megaloblastic anemia, lethargy, failure to thrive, developmental delay, intellectual deficit and seizures. There are four complementation classes of cobalamin defects (cblC, cblD, cblF and cblJ) that are responsible for methylmalonic acidemia - homocystinuria (methylmalonic acidemia - homocystinuria cblC, cblD cblF and cblJ).


Classification level: Disorder
  • Synonym(s):
    • Combined defect in adenosylcobalamin and methylcobalamin synthesis
    • Methylmalonic aciduria with homocystinuria
  • Prevalence: Unknown
  • Inheritance: Autosomal recessive or X-linked recessive 
  • Age of onset: All ages
  • ICD-10: E71.1
  • OMIM: 277380  277400  277410  614857
  • UMLS: C1848561
  • MeSH: C537359
  • GARD: 3579
  • MedDRA: -
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