Mondo Description Methylmalonic aciduria due to transcobalamin receptor defect is a rare metabolite absorption and transport disorder characterized by a moderate increase of methylmalonic acid (MMA) in the blood and urine due to decreased cellular uptake of cobalamin resulting from decreased transcobalamin receptor function. Patients are usually asymptomatic however, screening reveals increased C3-acylcarnitine and MMA in plasma. Serum homocysteine levels may vary from normal to moderately elevated and retinal vascular occlusive disease, resulting in severe visual loss, has been reported.

Uniprot Description A metabolic disorder characterized by increased blood C3-acylcarnitine levels, elevated methylmalonate and homocysteine, and low uptake of transcobalamin-bound cobalamin, but normal conversion to adenosylcobalamin and methylcobalamin.

Disease Ontology Description A methylmalonic acidemia characterized by autosomal recessive inheritance of low uptake of transcobalamin-bound cobalamin, but normal conversion to adenosylcobalamin and methylcobalamin and that has_material_basis_in mutation in the CD320 gene.