title: DHPR activity decrease in dried blood spots stored at 4 degrees C.
abstract: Dihydropteridine reductase (DHPR) activity has been measured in dried blood spots by the Arai method in 286 subjects divided into 4 groups: 45 newborns aged between 4 and 7 days; 40 subjects with hyperphenylalainaemia; 199 apparently normal subjects, and 2 patients with DHPR deficiency. Furthermore, a study of the persistence of enzymatic activity on the spots stored at 4 degrees C revealed that after 1 year it decreased to one third of the original value, corresponding to the mean value of controls minus 2 SD.
authors.affiliation: Department of Paediatrics, University of Florence, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Lenzi
authors.forename: D
authors.initials: D
authors.lastname: Pistone
authors.forename: E
authors.initials: E
authors.lastname: Zammarchi
authors.forename: M P
authors.initials: MP
authors.lastname: Benini
authors.forename: A
authors.initials: A
authors.lastname: La Torre
authors.forename: D
authors.initials: D
authors.lastname: Matteoni
mesh_terms: D000592:Amino Acid Metabolism, Inborn Errors / Q000097:blood / Q000201:enzymology; D001800:Blood Specimen Collection; D003080:Cold Temperature; D003890:Desiccation; D004093:Dihydropteridine Reductase / Q000097:blood*; D004795:Enzyme Stability; D006801:Humans; D007231:Infant, Newborn; D009247:NADH, NADPH Oxidoreductases / Q000097:blood*; D010649:Phenylalanine / Q000378:metabolism; D010661:Phenylketonurias; D012016:Reference Values
chemical_list: D010649:Phenylalanine; D004093:Dihydropteridine Reductase; D009247:NADH, NADPH Oxidoreductases