title: Blood spots on Guthrie cards can be used for inherited tetrahydrobiopterin deficiency screening in hyperphenylalaninaemic infants.
abstract: We describe a method of screening for dihydropteridine reductase deficiency and dihydrobiopterin synthesis deficiency--the two inherited defects that cause tetrahydrobiopterin deficiency--using blood spots on Guthrie cards. Dihydropteridine reductase deficiency may be identified positively, and a biopterin value of less than 6.0 micrograms/l in the presence of hyperphenylalaninaemia indicates further investigation for dihydrobiopterin synthesis deficiency.
mesh_terms: D000293:Adolescent; D000328:Adult; D001708:Biopterins / Q000031:analogs & derivatives / Q000096:biosynthesis / Q000097:blood / Q000172:deficiency*; D002648:Child; D002675:Child, Preschool; D004093:Dihydropteridine Reductase / Q000097:blood; D006801:Humans; D007231:Infant, Newborn; D008722:Methods; D010649:Phenylalanine / Q000097:blood*; D010661:Phenylketonurias; D011621:Pteridines / Q000172:deficiency*; D013048:Specimen Handling
chemical_list: D011621:Pteridines; D001708:Biopterins; D010649:Phenylalanine; C017226:7,8-dihydrobiopterin; D004093:Dihydropteridine Reductase; C003402:sapropterin