title: Phenylalanine hydroxylase deficiency in the Slovak population: genotype-phenotype correlations and genotype-based predictions of BH4-responsiveness.
abstract: We investigated the mutation spectrum of the phenylalanine hydroxylase gene (PAH) in a cohort of patients from 135 Slovak PKU families. Mutational screening of the known coding region, including conventional intron splice sites, was performed using high-resolution melting analysis, with subsequent sequencing analysis of the samples showing deviated melting profiles compared to control samples. The PAH gene was also screened for deletions and duplications using MLPA analysis. Forty-eight different disease causing mutations were identified in our patient group, including 30 missense, 8 splicing, 7 nonsense, 2 large deletions and 1 small deletion with frameshift; giving a detection rate of 97.6%. The most prevalent mutation was the p.R408W, occurring in 47% of all alleles, which concurs with results from neighboring and other Slavic countries. Other frequent mutations were: p.R158Q (5.3%), IVS12+1G>A (5.3%), p.R252W (5.1%), p.R261Q (3.9%) and p.A403V (3.6%). We also identified three novel missense mutations: p.F233I, p.R270I, p.F331S and one novel variant: c.-30A>T in the proximal part of the PAH gene promoter. A spectrum of 84 different genotypes was observed and a genotype based predictions of BH4-responsiveness were assessed. Among all genotypes, 36 were predicted to be BH4-responsive represented by 51 PKU families. In addition, genotype-phenotype correlations were performed.
authors.affiliation: Comenius University, Faculty of Natural Sciences, Department of Molecular Biology, Mlynska Dolina, 842 15 Bratislava, Slovak Republic. polakemo@gmail.com
authors.forename: Emil
authors.initials: E
authors.lastname: Polak
authors.forename: Andrej
authors.initials: A
authors.lastname: Ficek
authors.forename: Jan
authors.initials: J
authors.lastname: Radvanszky
authors.forename: Andrea
authors.initials: A
authors.lastname: Soltysova
authors.forename: Otto
authors.initials: O
authors.lastname: Urge
authors.forename: Eleonora
authors.initials: E
authors.lastname: Cmelova
authors.forename: Dana
authors.initials: D
authors.lastname: Kantarska
authors.forename: Ludevit
authors.initials: L
authors.lastname: Kadasi
mesh_terms: D000483:Alleles; D001483:Base Sequence; D001708:Biopterins / Q000031:analogs & derivatives / Q000627:therapeutic use; D056905:Chromosome Breakpoints; D017353:Gene Deletion; D005787:Gene Frequency; D056726:Genetic Association Studies; D005838:Genotype; D006801:Humans; D009154:Mutation; D059645:Mutation Rate; D010651:Phenylalanine Hydroxylase / Q000235:genetics* / Q000378:metabolism; D010661:Phenylketonurias / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics*; D011379:Prognosis; D018154:Slovakia; D016896:Treatment Outcome; D044465:White People / Q000235:genetics*
chemical_list: D001708:Biopterins; D010651:Phenylalanine Hydroxylase; C003402:sapropterin
keywords: BH4; BH4-responsiveness; BIOPKUdb; Bp; Conc.; EDTA; HPA; HRM; High Resolution Melting; HumVar; International Database of Patients and Genotypes Causing HPA/PKU including BH4-responsive Phenotype; International database of variations in Phenylalanine Hydroxylase gene; Kb; MC; MHP; MLPA; Multiplex Ligation-dependent Probe Amplification; Mutation analysis; PAH; PAH Locus Knowledgebase; PAHdb; PAHvdb; PCR; PKU; PRA; Phe; Phenylketonuria; RFLP; Ta; Taq; Thermus aquaticus; Tyr; U; annealing temperature; base pairs; cPKU; classic phenylketonuria; concentration; dNTP; deoxyribonucleoside triphosphate; ethylenediaminetetraacetic acid; gene encoding phenylalanine hydroxylase; human variation; hyperphenylalaninemia; kilobases; mPKU; mRNA; melting curve; messenger RNA; mild hyperphenylalaninemia; mild phenylketonuria; phenylalanine; phenylalanine hydroxylase; phenylketonuria; polymerase chain reaction; predicted residual activity; restriction-fragment length polymorphism; tetrahydrobiopterin (6RL-erythro-5,6,7,8-tetrahydrobiopterin); tyrosine; unit