syndromic disease inborn disorder of amino acid metabolism arakawa syndrome 2 SCTID:89579000 NCIT:C99081 A rare autosomal dominant inherited metabolic disorder characterized by deficiency of the enzyme tetrahydrofolate-methyltransferase. It results in the abnormal metabolism of methylcobalamin. Signs and symptoms include mental retardation, megaloblastic anemia, hypotonia, epilepsy, and hepatosplenomegaly. MONDO:0021915 N5-methylhomocysteine transferase deficiency MEDGEN:75697 MESH:C537426 methylcobalamin deficiency, cblG type Arakawa's syndrome II tetrahydrofolate methyltransferase deficiency methionine synthase deficiency Arakawa syndrome II homocystinuria-megaloblastic Anemia, cblG complementation type tetrahydrofolate-methyltransferase deficiency syndrome NANDO:2201111 GARD:0008265 UMLS:C0268611 Arakawa's syndrome 2