Arakawa's syndrome II

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.

Additional recommended knowledge

Essential Laboratory Skills Guide

Daily Sensitivity Test

Weighing the right way

It is also called Methionine synthase deficiency, Tetrahydrofolate-methyltransferase deficiency syndrome, and N5-methylhomocysteine transferase deficiency.

Presentation

This disorder causes neurological problems, including mental retardation, brain atrophy and ventricular dilation, myoclonus, hypotonia, and epilepsy.

It is also associated with growth retardation, megaloblastic anemia, pectus excavatum, scoliosis, vomiting, diarrhea, and hepatosplenomegaly. Inheritance is autosomal dominant.

Eponym

It is often called "Arakawa syndrome 2" after Tsuneo Arakawa;^[1][2] in this context, "Arakawa syndrome 1" refers to Glutamate formiminotransferase deficiency.

References

1. ^ synd/235 at Who Named It
2. ^ Arakawa T, et al (1967). "Megaloblastic anemia and mental retardation associated with hyperfolic-acidemia: probably due to N5 methyltetrahydrofolate transferase deficiency". Tohoku J. Exp. Med. 93 (1): 1-22. PMID 5300832.