Human Mutation RAPID COMMUNICATION Positive Newborn Screen for Methylmalonic Aciduria Identifies the First Mutation in TCblR/CD320, the Gene for Cellular Uptake of Transcobalamin-bound Vitamin B12
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چکیده
Elevated methylmalonic acid in five asymptomatic newborns whose fibroblasts showed decreased uptake of transcobalamin-bound cobalamin (holo-TC), suggested a defect in the cellular uptake of cobalamin. Analysis of TCblR/CD320, the gene for the receptor for cellular uptake of holo-TC, identified a homozygous single codon deletion, c.262_264GAG (p.E88del), resulting in the loss of a glutamic acid residue in the low-density lipoprotein receptor type A-like domain. Inserting the codon by sitedirected mutagenesis fully restored TCblR function. Hum Mutat 31:924–929, 2010. & 2010 Wiley-Liss, Inc.
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