Molybdenum cofactor deficiency

Molybdenum cofactor (MoCo) deficiency presents classically in the neonatal period, with convulsions intractable to anticonvulsant therapy and coma. The clinical manifestations of MoCo deficiency relating to the nervous system are generally considered to be functions of the deficiency of sulfite oxidase. Deficiency of xanthine oxidase leads to elevations in levels of xanthine, as well as hypouricemia. Xanthine is highly insoluble, and this leads to urinary tract calculi, hematuria, renal colic, and infection. Urinary excretion of sulfite, thiosulfate, S-sulfocysteine, and taurine were increased. There was hypouricemia and decreased excretions of uric acid and sulfate. The primary defect was deficient synthesis of the MoCo. Six patients with MoCo deficiency have been treated with this intermediate, now known as cyclic pyranopterin monophosphate. All were type A and had mutations in MOCS1 which causes a loss of cyclic pyranopterin monophosphate, the first intermediate in the pathway of molybdopterin synthesis.