{Reference Type}: Case Reports
{Title}: Transcobalamin deficiency - a rare genetic defect in transportation of cobalamin; case report.
{Author}: Iqbal N;Meghani MA;Khalid W;Ansari AH;Ansari MUH;Ansari SH;
{Journal}: Ann Hematol
{Volume}: 103
{Issue}: 8
{Year}: 2024 Aug 8
{Factor}: 4.03
{DOI}: 10.1007/s00277-024-05878-7
{Abstract}: <B>BACKGROUND: </B>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.<BR><B>METHODS: </B>We 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.<BR><B>CONCLUSIONS: </B>In patients with unresolved pancytopenia and megaloblastic anemia, Transcobalamin deficiency should be investigated and treated promptly to prevent any irreversible and harmful outcome.