title: [Analysis of mutations in exon 7 of phenylalanine hydroxylase gene among children with phenylketonuria in Ningxia, China].
abstract: OBJECTIVE
  To investigate the type and frequency of mutations in exon 7 of phenylalanine hydroxylase (PAH) gene among children with phenylketonuria (PKU) in Ningxia, China and to provide a basis for the genetic diagnosis and prenatal diagnosis of PKU in this region.
  
  
  METHODS
  Direct sequencing of PCR product was performed to analyze the sequences of exon 7 and its flanking introns of 146 PAH alleles in 73 children with typical PKU (39 cases of Hui nationality and 34 cases of Han nationality) in Ningxia.
  
  
  RESULTS
  Six mutations were detected, including R243Q (14.4%), R241C (6.8%), IVS7+2T→A (2.7%), L255S (0.7%), G247V (0.7%), and G247R (0.7%). The overall frequency of mutations (missense mutation and splice site mutation) in exon 7 was 26.0% (38/146). The detection rate of R241C mutation was significantly higher in children of Hui nationality than in children of Han nationality(10% vs 3%; P<0.05).
  
  
  CONCLUSIONS
  In Ningxia, R243Q mutation in exon 7 of PAH gene is most common in children with PKU, followed by R241C. The frequency of R241C mutation in exon 7 of PAH gene varies between children with PKU of Hui and Han nationality.
authors.affiliation: Maternal and Child Health Hospital of Ningxia Hui Autonomous Region, Yinchuan 750004, China. yuwz2013@126.com.
authors.forename: Xin-Mei
authors.initials: XM
authors.lastname: Mao
authors.forename: Jiang
authors.initials: J
authors.lastname: He
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.forename: Xiao-Qiang
authors.initials: XQ
authors.lastname: Li
authors.forename: Wu-Zhong
authors.initials: WZ
authors.lastname: Yu
authors.forename: Zhi-Hui
authors.initials: ZH
authors.lastname: Gao
authors.forename: Jing
authors.initials: J
authors.lastname: Cai
mesh_terms: D002681:China / Q000208:ethnology; D005091:Exons; D006801:Humans; D009154:Mutation; D010651:Phenylalanine Hydroxylase / Q000235:genetics*; D010661:Phenylketonurias / Q000235:genetics*
chemical_list: D010651:Phenylalanine Hydroxylase