Details

Autor(en) / Beteiligte

• Haurani, Farid I.

Titel

Cobalamins and folates as seen through inborn errors of metabolism: A review and perspective

Ist Teil von

• Vitamins and Hormones, 2000, Vol.60, p.353-381

Ort / Verlag

United States: Elsevier Science & Technology

Erscheinungsjahr

2000

Quelle

MEDLINE

Beschreibungen/Notizen

• This chapter discusses the inborn errors of metabolism that helps to understand the normal metabolism of folates and cobalamins, especially how they relate to the normoblastic development of the bone marrow, and megaloblastic anemia. The chapter provides information about the metabolism of these two vitamins and reviews some of the research techniques and their limitations. Selective patients with inborn errors of folate and cobalamin metabolism, and the concepts evolving from such errors, are presented in the chapter. Most biochemical studies done on megaloblastic anemia in the past were on bone marrow aspirates. These studies focused on the deoxyuridine suppression test. Dihydrofolate (DHF), an end product of de novo thymidine synthesis, is not reduced to tetrahydrofolate in the bone marrow as it has been shown that most of the dividing bone marrow cells have little or no dihydrofolate reductase activity. It is suggested that the constant supply of reduced folates to the bone marrow is derived from plasma formyltetrahydrofolates (formylTHFs). The inborn errors involving 5,10-methylenetetrahydrofolate reductase (MTHFR) and methionine synthase (MS) reactions support this conclusion. An alternative route could be the formylation of THF.