Mutation and haplotype analysis of phenylalanine hydroxylase alleles in classical PKU patients from the Czech Republic: identification of four novel mutations.

Abstract

Mutations, haplotypes, and other polymorphic markers in the phenylalanine hydroxylase (PAH) gene were analysed in 133 unrelated Czech families with classical phenylketonuria (PKU). Almost 95% of all mutant alleles were identified, using a combination of PCR and restriction analysis, denaturing gradient gel electrophoresis (DGGE), and sequencing. A total of 30 different mutations, 16 various RFLP/VNTR haplotypes, and four polymorphisms were detected on 266 independent mutant chromosomes. The most common molecular defect observed in the Czech population was R408W (54.9%). Each of the other 29 mutations was present in no more than 5% of alleles and 13 mutations were found in only one PKU allele each (0.4%). Four novel mutations G239A, R270fsdelSbp, A342P, and IVSlnt-8g--a-a were identified. In 14 (5.1%) alleles, linked to four different RFLP/VNTR haplotypes, the sequence alterations still remain unknown. Our results confirm that PKU is a heterogeneous disorder at the molecular level. Since there is evidence for the gene flow coming from northern, western, and southern parts of Europe into our Slavic population, it is clear that human migration has been the most important factor in the spread of PKU alleles in Europe.

Spectrum of low density lipoprotein receptor mutations in Czech hypercholesterolemic patients

“…The electrophoresis was carried out according to the procedures described previously (Kozak et al 1997). …”

Phenylketonuria mutations in Europe

“…There are incomplete data sets for the European part of Russia and other states of the former Soviet Union [Charikova et al, 1993;Baranovskaya et al, 1996]; recent data from the Ukraine have been published in abstract format [Nechyporenko and Livshits, 2002]. Apart from a high frequency of R408W-H2, PKU is quite heterogeneous in the Czech Republic [Kozak et al, 1997]. Relatively high frequencies of mutations R158Q, R261Q, and IVS12+1G4A have been reported from Slovakia [Kadasi et al, 1995].…”

Genetic diversity within the R408W phenylketonuria mutation lineages in Europe

“…Data on the relative allele frequency and PAH haplotype associations of the R408W mutation in 23 European regions and countries were drawn from the literature [Eisensmith et al, 1995;Kozak et al, 1997;Zschocke et al, 1997;Desviat et al, 1999;Giannattasio et al, 2001;Nechyporenko et al, 2001;O'Donnell et al, 2002;Kasnauskiene et al, 2003]. Absolute allele frequencies were estimated as the product of the square root of the disease incidence and the relative frequency of the mutation on the assumption of Hardy-Weinberg equilibrium [Bodmer and Cavalli-Sforza, 1971], using data on the incidence of PKU drawn from the literature and from collaborating laboratories.…”