title: [Anemias due to disorder of folate, vitamin B12 and transcobalamin metabolism].
abstract: Macrocytic megaloblastic anemia is the most typical but the latest sign of a cobalamin (vitamin B12) and/or folic acid deficiency or of a congenital abnormality of cobalamin and folate metabolism. Macrocytosis in blood and megaloblastosis in bone marrow are the morphological features of a disturbance in cell division related to a defect in DNA biosynthesis. Macrocytosis without anemia, normocytic normochronic anemia with a low reticulocyte cell count or microcytic hypochromic anemia in case of associated iron deficiency do not exclude a vitamin deficiency. Neurological or psychiatric disorders and immune abnormalities have been reported in patients with vitamin B12 or folate deficiencies or in children with congenital abnormalities of these 2 vitamins; such manifestations may even occur without anemia.
authors.affiliation: Laboratoire central d'hématologie-immunologie, hôpital Henri-Mondor, Créteil.
authors.forename: J
authors.initials: J
authors.lastname: Zittoun
mesh_terms: D000749:Anemia, Megaloblastic / Q000175:diagnosis / Q000209:etiology* / Q000378:metabolism / Q000628:therapy; D003937:Diagnosis, Differential; D005492:Folic Acid / Q000378:metabolism*; D006801:Humans; D008659:Metabolic Diseases / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy; D014155:Transcobalamins / Q000378:metabolism*; D014805:Vitamin B 12 / Q000378:metabolism*
chemical_list: D014155:Transcobalamins; D005492:Folic Acid; D014805:Vitamin B 12
vernacular_title: Anémies par trouble du métabolisme des folates, de la vitamine B12 et des transcobalamines.