Congenital transcobalamin II deficiency due to errors in RNA editing
| Autor: | Annette Regec, Edward V. Quadros, Jacqueline Zittoun, Sheldon P. Rothenberg, Lian Qian |
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| Rok vydání: | 2002 |
| Předmět: |
Male
Anemia Megaloblastic Biology Complementary DNA medicine Humans Northern blot Vitamin B12 RNA Messenger Megaloblastic anemia Molecular Biology Gene Genetics Transcobalamins Reverse Transcriptase Polymerase Chain Reaction Sequence Analysis RNA Genetic disorder Genetic Diseases Inborn Infant Cell Biology Hematology Sequence Analysis DNA Fibroblasts medicine.disease Molecular biology genomic DNA Vitamin B 12 RNA editing Molecular Medicine Female RNA Editing Protein Binding |
| Zdroj: | Blood cells, moleculesdiseases. 28(2) |
| ISSN: | 1079-9796 |
| Popis: | Transcobalamin II (TCII) is a plasma protein essential for the transport and cellular uptake of vitamin B12 (B12; cobalamin, Cbl). Congenital deficiency of functional TCII is an autosomal recessive genetic disorder that results in clinical B12 deficiency usually within several months following birth. In this report, we describe the molecular basis for TCII deficiency in two patients who developed a megaloblastic anemia in early infancy. The serum of both patients contained immunoreactive TCII that did not bind [57Co]Cbl. The fibroblasts from each patient secreted a similarly nonfunctional TCII, yet full-length TCII transcripts were identified by Northern blot. Overlapping cDNA fragments were generated by reverse transcription-polymerase chain reaction and several mutations were identified in the coding region of the cDNA, one of which was common to both patients. However, amplification of the corresponding regions of the gene from genomic DNA failed to identify these mutations. These findings were confirmed by replicate analyses and support the proposal that a variance in RNA editing is the likely mechanism for the mutations that resulted in the expression of a nonfunctional TCII protein in these patients. |
| Databáze: | OpenAIRE |
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