[Study on mutations of exon 12 of the PAH gene in 127 phenylketonuria patients].
OBJECTIVE
To obtain the mutation spectrum of exon 12 of the phenylalanine hydroxylase(PAH) gene.


METHODS
The samples from 127 patients with phenylketonuria(PKU) were studied by polymerase chain reaction(PCR)-single strand conformation polymorphism(SSCP)  PCR-denaturing gradient gel electrophoresis(DGGE) and direct DNA sequencing.


RESULTS
Four heterozygous mutations including R413P  S411X  R408W  R408Q in 10 of 127 patients were identified by DNA sequencing. The frequencies of R413P  S411X  R408W  R408Q mutation were 2.76%, 0.39%, 0.39% and 0.39%, respectively. The S411X mutation in Chinese was first reported. Only 2 cases with R413P mutation were detected by SSCP. DGGE analysis showed that 10 cases displayed 3 kinds of abnormal electrophoretic bands. There were no obvious differences in the frequency of R413P mutation between northern and southern Chinese with PKU, and between classical PKU and hyperphenylalaninemia.


CONCLUSIONS
DGGE is more sensitive than SSCP in screening the mutations of exon 12 of the PAH gene. DGGE combined with DNA sequencing can be used to define all the mutations of exon 12 of the PAH gene. These results indicate the similarity in the frequency of R413P mutation between northern and southern patients.
Qiu
Wen-juan
WJ
Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital Shanghai Second Medical University, Shanghai Institute for Pediatric Research, Shanghai, 200092 PR China. wenjuan_qiu @sina.com
Zhang
Ya-fen
YF
Ye
Jun
J
Han
Lian-shu
LS
Gu
Xue-fan
XF
D004591:Electrophoresis, Polyacrylamide Gel; D005091:Exons; D006801:Humans; D009154:Mutation; D010651:Phenylalanine Hydroxylase / Q000235:genetics*; D010661:Phenylketonurias / Q000235:genetics*; D018807:Polymorphism, Single-Stranded Conformational; D017422:Sequence Analysis, DNA
D010651:Phenylalanine Hydroxylase