NEWBORN SCREENING FOR HOMOCYSTINURIA

It is becoming increasingly apparent that pyridoxine responsive homocy stinuria patients are being missed by newborn screening programs. The possibility that screening for homocystine, rather than the methionine , might be more effective was investigated by comparing homocystine an d methionine levels of non-responsive patients at diagnosis. The plasm a methionine levels of 11 infants were much more abnormal than the hom ocystine levels. Urine homocystine was low or not detectable and alway s less than methionine. Therefore, methionine determination is much mo re effective than homocystine determination for newborn screening for homocystinuria. It seems that a second blood specimen at a later age m ay be required to find the pyridoxine responsive infants. (C) 1997 Els evier Science Ireland Ltd.