MOLYBDENUM-COFACTOR DEFICIENCY - AN EASILY MISSED CAUSE OF NEONATAL CONVULSIONS

Intractable seizures in the neonatal period may be caused by molybdenu m-cofactor deficiency, an inborn error which combines the deficiencies of sulphite oxidase and xanthine dehydrogenase. The neurological symp toms of molybdenum cofactor and isolated sulphite oxidase deficiencies are identical. Two new cases are reported, and the literature on neon atal convulsions due to molybdenum-cofactor and sulphite deficiencies is reviewed. Because of the high incidence of neonatal convulsions a s earch for this deficiency is advocated in each case of unexplained ref ractory neonatal convulsions. Diagnosis may be missed or delayed on st andard metabolic screening for several reasons discussed. By simply us ing a sulphite strip test in a fresh urine sample an indication for th e defect can be obtained. Antenatal diagnosis can be performed by assa y of sulphite oxidase activity in a chorionic villus sample.