Cobalamin C Mutation (Methylmalonic Aciduria and Homocystinuria) in Adolescence

Abstract

DISORDERS of cobalamin (vitamin B₁₂) can be divided into those associated with a deficiency of this essential cofactor and those due to inborn metabolic errors. When they are a result of an inborn error of metabolism, symptoms usually appear in infancy and consist of failure to thrive, developmental retardation, seizures, and hematologic abnormalities.^{1 2 3 4 5 6 7 8 9 10} In contrast, cobalamin-deficiency disorders generally occur in adulthood and are associated with megaloblastic anemia, subacute combined degeneration, and mental disturbances.¹¹ In this report, we describe an adolescent girl with progressive dementia and myelopathy secondary to a familial intracellular defect of B]2 metabolism (cobalamin C mutation), . . .