[Molybdenum cofactor deficiency. Clinical symptoms and diagnostic strategy]

The clinical, neuroradiological and biochemical findings in two siblings with molybdenum cofactor deficiency are presented. A search for this deficiency is advocated in each case of unexplained refractory neonatal convulsions. Early diagnosis is prompted by the often rapid fatal outcome and the availability of methods for prenatal diagnosis. Diagnosis may be missed or delayed on standard metabolic screening for several reasons discussed. Magnetic resonance imaging in this condition seems to be rather characteristic.