Methylmalonic Aciduria and Homocystinuria, cobalamin C (cblC) Type

Methylmalonic aciduria and homocystinuria, cblC type, is a defect in B12 metabolism. Patients may present with severe early onset disease that includes megaloblastic and macrocytic anemia and failure to thrive, microcephaly, lethargy and feeding difficulties. Neurologic symptoms may include hypotonia, seizures, developmental delay, ataxia and optic atrophy. Late onset cases may present with neurologic symptoms such as anorexia, irritability, fatigue, myelopathy or dementia. Other complications are mental retardation, microcephaly, retinal degeneration, pigmentary retinopathy, microangiopathy and skin lesions.

Tests Available

Forms and Documents

Test Details

MMACHC
  • Confirmation of a biochemical/clinical diagnosis
  • Carrier testing
  • Prenatal diagnosis in at risk pregnancies
  • Capillary Sequencing

Ordering

274
3-4 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL)|Buccal Swabs

Billing

81404x1
No
Yes
  • 270.4 Disturbances of sulphur-bearing amino-acid metabolism, Cystathioninemia, Cystathioninuria, Disturbances of metabolism of methionine, homocystine, and cystathionine Homocystinuria, Hypermethioninemia, Methioninemia
  • 270.9 Unspecified disorder of amino-acid metabolism
* For price inquiries please email zebras@genedx.com

References

  1. Rosenblatt, DS and Fenton, WA (2001) Inherited disorders of folate and cobalamin transport and metabolism . In: C.R. Scriver, A.L. Beaudet, W.S. Sly and D. Valle (Eds)The Metabolic and Molecular Basis of Inherited Diseases, McGraw-Hill, NY
  2. Lerner-Ellis, JP et al., (2006) Nature Genet 38:93-100
  3. Rosenblatt, DS et al. (1985) Science 28:1319-1321
  4. Lerner-Ellis et al., (2009) Hum Mutat 30:1072-1081