Mutations identified in exon 7 of phenylalanine hydroxylase gene in Chinese.

Exon 7 of the phenylalanine hydroxylase (PAH) gene was analyzed in 45 children affected with classic phenylketonuria (PKU) from northern China by using PCR-single strand conformation polymorphism (PCR-SSCP) technique and DNA direct sequencing. Six missense mutations(i.e. R243Q, R241H, G247V, L249H, F2541 and G257V) and one silent mutation (V245v) were identified. The latter three missense mutations were demonstrated as novel mutations in comparison with the PAH mutation database. One missense mutation (R241H) was first documented in Chinese. Our results showed population and region differences in the PAH mutation distribution, and suggest that there is more than one founding population for PKU in China. The finding of novel mutations will enhence the molecular diagnosis of PKU.