Formiminotransferase deficiency syndrome associated with megaloblastic anemia responsive to pyridoxine or folic acid.

Formiminotransferase deficiency syndrome1,2 was firstly discovered by us as a new inborn error of folate metabolism which was characterized by 1) mental retardation, 2) hyperfolic acidemia, and 3) an excessive urinary excretion of formiminoglutamic acid (FIGLU) following an oral dose of L-histidine. A definite diagnosis of this syndrome was established by demonstrating a defective activity of formiminotransferase in the liver specimens obtained from patients in question. The purpose of our present paper is to describe an infant with formiminotrans ferase deficiency syndrome associated with megaloblastic-pyridoxine-folic acidresponsive anemia probably of congenital origin.