Transcobalamin II Deficiency

2020 ◽  
Author(s):  
Keyword(s):  
Transcobalamin Ii

scholarly journals Purification and molecular characterization of human transcobalamin II.

1986 ◽  
Vol 261 (33) ◽  
pp. 15455-15460 ◽  
Author(s):  
E V Quadros ◽  
S P Rothenberg ◽  
Y C Pan ◽  
S Stein
Keyword(s):  
Molecular Characterization ◽  
Transcobalamin Ii

scholarly journals Neurological involvement in hereditary transcobalamin II deficiency.

1982 ◽  
Vol 45 (1) ◽  
pp. 74-77 ◽  
Author(s):  
P K Thomas ◽  
A V Hoffbrand ◽  
I S Smith
Keyword(s):  
Neurological Involvement ◽  
Transcobalamin Ii

scholarly journals Vitamin B12 transport in blood. I. Congenital deficiency of transcobalamin II

Blood ◽  
1975 ◽  
Vol 45 (1) ◽  
pp. 71-82 ◽  
Author(s):  
E Gimpert ◽  
M Jakob ◽  
WH Hitzig
Keyword(s):  
Vitamin B12 ◽  
Binding Capacity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Congenital Deficiency ◽  
Complete Clinical Remission ◽  
High Concentrations ◽  
High Doses ◽  
Vitamin B12 Binder ◽  
Very High ◽  
Transcobalamin Ii

Abstract Some characteristics of vitamin B12 binding and transport in the serum of an infant with congenital hereditary transcobalamin II (TC II) deficiency were studied using the following parameters and methods: vitamin B12 level and binding capacity; electrophoretic mobility in polyacrylamide gel electrophoresis; various immunodiffusion and absorption experiments, using a specific anti-TC II antiserum and the patient's serum as antigen. The results of these studies point to a deficient synthesis of TC II. Parenteral administration of high doses of vitamin B12 was followed by rapid and complete clinical remission and the appearance of vitamin B12 binder in the alpha 2 region which is similar to “fetal binder.” Thus, very high concentrations of vitamin B12, either carrier free or bound to this alpha 2 binder, were able to correct the disturbed physiology of TC II deficiency, presumably by normalization of DNA-thymine synthesis.

The Carriers of Native Vitamin B12 in Normal Human Serum

1977 ◽  
Vol 53 (5) ◽  
pp. 453-457 ◽  
Author(s):  
C. A. Hall
Keyword(s):  
Vitamin B12 ◽  
Human Serum ◽  
Isotope Dilution ◽  
Serum Vitamin ◽  
Total Serum ◽  
Plasma Vitamin ◽  
Isotope Dilution Assay ◽  
Dilution Assay ◽  
Normal Human ◽  
Transcobalamin Ii

1. After fractionation of the vitamin B12-binding proteins of ten normal sera the components containing transcobalamin II and R-type binders of vitamin B12 respectively were studied for endogenous vitamin B12 content by two distinct systems of vitamin B12 assay. 2. The measurements of total serum vitamin B12 by either bioassay with Euglena gracilis or a radioisotope dilution assay agreed closely. 3. The native vitamin B12 carried by transcobalamin II was higher as measured by bioassay than by isotope dilution assay. 4. The presence of the transcobalamin II fraction of human serum altered the key reaction between the binding reagent of the isotope dilution assay, so that this assay failed to measure vitamin B12 quantitatively. 5. Probably, the mean fraction of plasma vitamin B12 carried by transcobalamin II is in the range 20–30%.

scholarly journals Homozygous transcobalamin II deficiency maintained on oral hydroxocobalamin

Blood ◽  
1985 ◽  
Vol 66 (5) ◽  
pp. 1022-1027
Author(s):  
HC Zeitlin ◽  
K Sheppard ◽  
JD Baum ◽  
FG Bolton ◽  
CA Hall
Keyword(s):  
Family Study ◽  
Extended Family ◽  
Single Gene ◽  
Gel Filtration ◽  
Normal Subjects ◽  
Clear Separation ◽  
Total Absence ◽  
Transcobalamin Ii

A case of transcobalamin II (TCII) deficiency in which a total absence of TCII was demonstrated both functionally and immunologically is reported. Unlike previously described patients, this child has been maintained on oral hydroxocobalamin, 2 mg daily, without any parenteral supplementation for the last five years. At the age of six years her development is normal and her health is good. Plasma cobalamin levels are in the range of 3,000 ng/L and most of this appears to be bound to a molecule, which on gel filtration, elutes with albumin. In an extended family study, a clear separation of heterozygotes from both the propositus and from normal subjects suggests that the underlying defect in this condition is confined to a single gene.

Synthesis of transcobalamin II by cultured human hepatocytes

1985 ◽  
Vol 838 (3) ◽  
pp. 387-389 ◽  
Author(s):  
Charles A. Hall ◽  
Pamela D. Green-Colligan ◽  
James A. Begley
Keyword(s):  
Human Hepatocytes ◽  
Transcobalamin Ii
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