Arakawa's syndrome II
is an inborn error of metabolism
, a genetic disorder
that causes a deficiency of the enzyme tetrahydrofolate-methyltransferase
; affected individuals cannot properly metabolize methylcobalamin
, a type of Vitamin B12
It is also called Methionine synthase deficiency, Tetrahydrofolate-methyltransferase deficiency syndrome, and N5-methylhomocysteine transferase deficiency.
This disorder causes neurological
problems, including mental retardation
, brain atrophy
, and epilepsy
It is also associated with growth retardation, megaloblastic anemia, pectus excavatum, scoliosis, vomiting, diarrhea, and hepatosplenomegaly. Inheritance is autosomal dominant.
It is often called "Arakawa syndrome 2" after Tsuneo Arakawa
; in this context, "Arakawa syndrome 1" refers to Glutamate formiminotransferase