Transcobalamin Deficiency with the Mutation of Tcn2 in Children with the Primary Diagnosis of Methylmalonic Academia

Transcobalamin deficiency as a rare autosomal recessive disorder and methylmalonic acidemia is an autosomal recessive disorder of amino acid metabolism. Based on the common presentation of methylmalonic academia and Transcobalamin deficiency, in this case report, we presented rare cases of Transcobalamin deficiency in children with the primary diagnosis of methylmalonic academia. As the genetic test indicated the definite diagnosis, we fortunately treated our patient based on the genetic result to solve B12 deficiency and it showed promising outcomes.