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Methylmalonic acidemia with homocystinuria, type cblC

Disease definition

cblC type methylmalonic acidemia with homocystinuria is a form of methylmalonic acidemia with homocystinuria (see this term), an inborn error of vitamin B12 (cobalamin) metabolism characterized by megaloblastic anemia, lethargy, failure to thrive, developmental delay, intellectual deficit and seizures.

ORPHA:79282

Classification level: Subtype of disorder
  • Synonym(s):
    • CblC defect
    • Cobalamin C defect
    • Combined defect in adenosylcobalamin and methylcobalamin synthesis, type cblC
    • Methylmalonic aciduria with homocystinuria, type cblC
  • Prevalence: Unknown
  • Inheritance: Autosomal recessive 
  • Age of onset: All ages
  • ICD-10: D58.8
  • ICD-11: 5C50.E0
  • OMIM: 277400
  • UMLS: -
  • MeSH: -
  • GARD: 12128
  • MedDRA: -

Summary

Epidemiology

To date, over 500 cases of cblC have been reported, making it the most frequent type of methylmalonic acidemia with homocystinuria.

Clinical description

The disease typically presents with failure to thrive, acute neurological deterioration, intellectual deficit, lethargy, seizures, microcephaly, a salt-and-pepper retinopathy, and signs of megaloblastic anemia (pallor, fatigue, anorexia). Severe brain abnormalities including hydrocephalus, white matter abnormalities, cerebral atrophy, and unusual basal ganglia lesions are common. Onset of the disorder can be early (infantile) or late (juvenile or adult), with the late-onset form characterized by ataxia, dementia and psychosis.

Etiology

cblC type methylmalonic acidemia with homocystinuria is caused by mutations in the MMACHC gene (1p36.3) and is transmitted in an autosomal recessive manner.

Expert reviewer(s):  Dr David ROSENBLATT - Dr David WATKINS - Last update: March 2012

  A summary on this disease is available in Deutsch (2012) Español (2012) Français (2012) Italiano (2012) Nederlands (2012) Português (2012) Polski (2012, pdf)

Detailed information

General public

Guidelines

Disease review articles

ERN : produced/endorsed by ERN(s)
FSMR : produced/endorsed by FSMR(s)

Additional information

Further information on this disease

Patient-centred resources for this disease

Research activities on this disease

Specialised Social Services

The documents contained in this web site are presented for information purposes only. The material is in no way intended to replace professional medical care by a qualified specialist and should not be used as a basis for diagnosis or treatment.