ABSTRACT
Objective To determine the spectrum of mutations responsible for Phenylalanine hydroxylase (PAH) deficiency on phenylketonuria (PKU) patients of Han Chinese people in the Huaihai region of central China.Methods One hundred and one patients diagnosed with PKU were referred to Xuzhou Maternity and Child Health Care Hospital for genetic counseling/analysis from January 2003 to December 2013.Thirteen exons of PAH gene mutations,as well as their flanking introns,were identified in 202 of chromosomes using polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP) and sequencing.Results (1) The spectrum was composed of 24 different mutation types,which had been submitted to the National Center for Biotechnology Information(NCBI) dbSNP databases under accession number SS#2137543837_SS#C2137543860.(2)The most commonly affected region was exon 7 and its flanking introns.The most prevalent mutations were c.728G ＞ A (p.R243Q),followed by c.721C ＞ T (p.R241C),c.1155G ＞ C(p.L385L),c.1068C ＞ A(p.Y356X),c.-71A ＞ C(-71A ＞ C) and c.60 + 62C ＞ T (IVS1 +62C ＞T),accounting for 18.317％,8.416％,4.950％,3.960％,3.465％ and 2.970％ of the mutant chromosomes,respectively.(3)Two novel mutations were identified in PAH gene in PKU patients of Han Chinese people:c.60+62C＞T(IVS1 +62C ＞T) and c.782G ＞T(p.R261L).Conclusions The vast majority of PAH mutations identified corresponded to those observed for the PKU populations in the other regions in China,whereas a few are considerably different from others.The mutational spectrum of PAH gene found in patients with PKU in the Huaihai region exhibit regional association.