title: Combined methylmalonic acidemia and homocystinuria, cblC type. I. Clinical presentations, diagnosis and management.
abstract: Combined methylmalonic acidemia and homocystinuria, cblC type, is an inborn error of intracellular cobalamin metabolism with a wide spectrum of clinical manifestations that is stated to be the most common inherited disorder of cobalamin metabolism. This metabolic disease is caused by mutations in the MMACHC gene and results in impaired intracellular synthesis of adenosylcobalamin and methylcobalamin, cofactors for the methylmalonyl-CoA mutase and methionine synthase enzymes. Elevated methylmalonic acid and homocysteine with decreased methionine production are the biochemical hallmarks of this disorder. Awareness of the diverse clinical presentations associated with cblC disease is necessary to provide a timely diagnosis, to guide management of affected individuals and to establish a framework for the future treatment of individuals detected through expanded newborn screening. This article reviews the biochemistry, clinical presentations, genotype-phenotype correlations, diagnosis and management of cblC disease.
authors: Organic Acid Research Section, Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Building 49, Room 4A18, Bethesda, MD 20892, USA.
authors: Nuria
authors: N
authors: Carrillo-Carrasco
authors: Randy J
authors: RJ
authors: Chandler
authors: Charles P
authors: CP
authors: Venditti
mesh_terms: D000293:Adolescent; D000592:Amino Acid Metabolism, Inborn Errors / Q000175:diagnosis* / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006712:Homocystinuria / Q000175:diagnosis* / Q000235:genetics*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008715:Methionine / Q000378:metabolism; D008764:Methylmalonic Acid / Q000378:metabolism; D008954:Models, Biological; D008957:Models, Genetic; D009154:Mutation; D015997:Neonatal Screening / Q000379:methods; D010088:Oxidoreductases; D011247:Pregnancy; D011296:Prenatal Diagnosis; D014805:Vitamin B 12 / Q000378:metabolism*; D014806:Vitamin B 12 Deficiency / Q000151:congenital
chemical_list: D002352:Carrier Proteins; D008764:Methylmalonic Acid; D008715:Methionine; C508359:MMACHC protein, human; D010088:Oxidoreductases; D014805:Vitamin B 12