Transcobalamin deficiency — a rare genetic defect in transportation of cobalamin; case report
摘要
Vitamin B12 is primarily transported from plasma to cells by Transcobalamin. Deficiency of Transcobalamin is a rare autosomal recessive disorder that results in unavailability of cobalamin in cells and accumulation of homocysteine and methylmalonic acid.
Case ReportWe report a case of a 2-year-old male child with persistent pancytopenia, recurrent infections, and megaloblastic anemia. Next-generation sequencing identified a novel variant in exon 8 of TCN2 gene. Substantial improvement has been observed following administration of high doses of parenteral methylcobalamin.
ConclusionIn patients with unresolved pancytopenia and megaloblastic anemia, Transcobalamin deficiency should be investigated and treated promptly to prevent any irreversible and harmful outcome.