Neurological involvement in hereditary transcobalamin II deficiency.

Hereditary partial transcobalamin II deficiency with neurologic, mental and hematologic abnormalities in children and adults.

BACKGROUND Transcobalamin II is a serum transport protein for vitamin B12. Small variations in TC-II affinity were recently linked to a high homocysteine level and increased frequency of neural tube defects. Complete absence of TC-II or total functional abnormality causes tissue vitamin B12 deficiency resulting in a severe disease with megaloblastic anemia and immunologic and intestinal abnorma...

Transcobalamin II Deficiency in Four Cases with Novel Mutations

OBJECTIVE Transcobalamin II deficiency is one of the rare causes of inherited vitamin B12 disorders in which the patients have characteristically normal or high vitamin B12 levels related to the transport defect of vitamin B12 into the cell, ending up with intracellular cobalamin depletion and high homocysteine and methylmalonic acid levels. MATERIALS AND METHODS Herein, we describe the findi...

Acquired and inherited disorders of cobalamin and folate in children.

Cobalamin deficiency in the newborn usually results from cobalamin deficiency in the mother. Megaloblastic anaemia, pancytopenia and failure to thrive can be present, accompanied by neurological deficits if the diagnosis is delayed. Most cases of spina bifida and other neural tube defects result from maternal folate and/or cobalamin insufficiency in the periconceptual period. Polymorphisms in a...

Congenital transcobalamin II deficiency presenting atypically with a low serum cobalamin level: studies demonstrating the coexistence of a circulating transcobalamin I (R binder) complex.

A case of transcobalamin II deficiency with several unique features is described. The clinical presentation was typical, except for a slightly delayed age at presentation and the occurrence of apparent neurologic dysfunction from the beginning. The unusual biochemical feature was a low serum cobalamin level (97 pg/ml). Several cobalamin-binding protein abnormalities coexisted and antedated coba...

Transcobalamin II G775C Polymorphism and Indices of Vitamin B12 Status in Healthy Older Adults Running Head: Transcobalamin II Genotype and B12 Status