title: Heterozygous carriers of classical phenylketonuria in a sample of the Turkish population: detection by a spectrofluorimetric method.
abstract: Blood obtained by finger prick from 209 presumed normal homozygotes and 42 heterozygotes for classical PKU was analyzed for plasma phenylalanine (Phe) and tyrosine (Tyr) by a fluorimetric method. Subjects were tested near midday and 3 hours after a protein-rich breakfast. The plot of Phe/Tyr (micromolar ratio) against Phe2/Tyr, permitted the detection of 11 heterozygotes among 209 controls. The accuracy of this method was checked by computation of a stepwise multivariate discriminant analysis, using Phe and Tyr (mumol/L), Phe/Tyr micromolar ratio and Phe2/Tyr as variables. Ten of the 11 subjects were recovered with a percentage of correct classification of over 90%, while one case had a percentage of 89.45%. The PKU gene frequency was found to be 1/19. This emphasizes the importance of a screening programme for PKU gene carrier status in Turkey.
authors.affiliation: Hacettepe University, Department of Pediatric Nutrition and Metabolism, Ankara, Turkey.
authors.forename: F
authors.initials: F
authors.lastname: Güneral
authors.forename: I
authors.initials: I
authors.lastname: Ozalp
authors.forename: H
authors.initials: H
authors.lastname: Tatlidil
mesh_terms: D000293:Adolescent; D000328:Adult; D016002:Discriminant Analysis; D005260:Female; D005787:Gene Frequency; D006580:Genetic Carrier Screening / Q000379:methods*; D006801:Humans; D008297:Male; D010649:Phenylalanine / Q000097:blood; D010661:Phenylketonurias / Q000097:blood / Q000235:genetics*; D013050:Spectrometry, Fluorescence; D014421:Turkey; D014443:Tyrosine / Q000097:blood
chemical_list: D014443:Tyrosine; D010649:Phenylalanine