Tags

Type your tag names separated by a space and hit enter

Congenital disorders of vitamin B12 transport and their contributions to concepts. II.
Yale J Biol Med. 1981 Nov-Dec; 54(6):485-95.YJ

Abstract

Congenital deficiencies of Transcobalamin II (TC II) and R binders of vitamin B12 (B12, cobalamin, Cbl) have been described in several families. The deficiency of TC II exists as at least three variants. The deficiency of TC II is expressed by a profound megaloblastic pancytopenia during the first few weeks of life, but the serum Cbl is normal. In contrast, the deficiency of R binder is asymptomatic, tissues are replete in Cbl, but the serum Cbl is low. All of the R binder in the several body sources is under the same genetic control. Studies of the congenital deficiency TC II suggest the following: (1) The function of TC II is the promotion of cell uptake of physiologic amounts of Cbl, which can also be accomplished by very large amounts of Cbl, and not in any intracellular process. (2) TC II is essential for the absorption, postabsorptive distribution, and recycling of TC II. (3) The metabolic consequences of TC II deficiency are expressed primarily in rapidly dividing cells probably because they are dependent upon the constant need for new Cbl.

Authors

No affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

7342493

Citation

Hall, C A.. "Congenital Disorders of Vitamin B12 Transport and Their Contributions to Concepts. II." The Yale Journal of Biology and Medicine, vol. 54, no. 6, 1981, pp. 485-95.
Hall CA. Congenital disorders of vitamin B12 transport and their contributions to concepts. II. Yale J Biol Med. 1981;54(6):485-95.
Hall, C. A. (1981). Congenital disorders of vitamin B12 transport and their contributions to concepts. II. The Yale Journal of Biology and Medicine, 54(6), 485-95.
Hall CA. Congenital Disorders of Vitamin B12 Transport and Their Contributions to Concepts. II. Yale J Biol Med. 1981 Nov-Dec;54(6):485-95. PubMed PMID: 7342493.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Congenital disorders of vitamin B12 transport and their contributions to concepts. II. A1 - Hall,C A, PY - 1981/11/1/pubmed PY - 1981/11/1/medline PY - 1981/11/1/entrez SP - 485 EP - 95 JF - The Yale journal of biology and medicine JO - Yale J Biol Med VL - 54 IS - 6 N2 - Congenital deficiencies of Transcobalamin II (TC II) and R binders of vitamin B12 (B12, cobalamin, Cbl) have been described in several families. The deficiency of TC II exists as at least three variants. The deficiency of TC II is expressed by a profound megaloblastic pancytopenia during the first few weeks of life, but the serum Cbl is normal. In contrast, the deficiency of R binder is asymptomatic, tissues are replete in Cbl, but the serum Cbl is low. All of the R binder in the several body sources is under the same genetic control. Studies of the congenital deficiency TC II suggest the following: (1) The function of TC II is the promotion of cell uptake of physiologic amounts of Cbl, which can also be accomplished by very large amounts of Cbl, and not in any intracellular process. (2) TC II is essential for the absorption, postabsorptive distribution, and recycling of TC II. (3) The metabolic consequences of TC II deficiency are expressed primarily in rapidly dividing cells probably because they are dependent upon the constant need for new Cbl. SN - 0044-0086 UR - https://www.unboundmedicine.com/medline/citation/7342493/Congenital_disorders_of_vitamin_B12_transport_and_their_contributions_to_concepts__II_ L2 - https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/7342493/ DB - PRIME DP - Unbound Medicine ER -