[Identification of novel mutations in the phenylalanine hydroxylase gene of classical phenylketonuria]

To investigate the mutations of phenylalanine hydroxylase (PAH) gene in the cases of classical phenylketonuria (PKU).The exons 3-12 of the PAH gene in 32 PKU patients from Inner Mongolia were studied by using PCR-single strand conformation polymorphism technique and DNA direct sequencing.Fourteen point mutations were identified. The frequencies of mutations were R243Q (12/64), Y356X (6/64), Y204C (5/64), R261Q (2/64), Y161S (2/64), R252Q (1/64), R111X (2/64), D282G (1/64), S303P (1/64), G239D (1/64), R413P (1/64), IVS7nt+2 (2/64), IVS4nt+3 (1/64) and IVS9nt+34 (2/64). Two novel mutations IVS4nt+3 (GC) and IVS9nt+34 (GA) were first found. The S303P (TC) and D282G (AG) were first documented in Chinese PAH gene.This study demonstrated the variety of the mutation type PAH gene of PKU in Inner Mongolia population, and confirmed that R243Q, Y356X, Y204C were the hot spots of PAH gene mutation.