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Expression of transcobalamin II by amniocytes
Author(s) -
Rosenblatt David S.,
Hosack Angela,
Matiaszuk Nora
Publication year - 1987
Publication title -
prenatal diagnosis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.956
H-Index - 97
eISSN - 1097-0223
pISSN - 0197-3851
DOI - 10.1002/pd.1970070107
Subject(s) - megaloblastic anemia , asymptomatic , amniotic fluid , fetus , medicine , biology , endocrinology , chemistry , andrology , pregnancy , anemia , genetics
Children with a genetic absence of transcobalarnin 2 (TC2) are clinically asymptomatic at birth but develop severe megaloblastic anemia early in life. We have examined the incorporation of [ 57 Co]‐CN‐B 12 in the absence of any exogenous source of TC2 in control amniotic fluid derived cells and cultured diploid fibroblasts, and in fibroblasts from a patient with TC2 deficiency. Both control fibroblasts and arnniocytes incorporated labelled B 12 , into TC2‐B 12 , and the proportion of labelled TC2‐B 12 could be increased by growing cells in the presence of chloroquine which prevents intralysosomal hydrolysis of the TC2‐B 12 complex. In contrast, fibroblasts from the patient with TC2 deficiency incorporated almost no label as TC2‐B 12 . These studies suggest that TC2 deficiency either due to aberrant production of TC2 or because of the production of an abnormal TC2 which does not bind B 12 can be diagnosed before birth.