目的探讨新疆南疆地区维吾尔族苯丙酮尿症(phenylketonuria,PKU)患儿苯丙氨酸羟化酶(phenylalanine hydroxylase,PAH)基因第5外显子的突变特征。方法应用PCR产物直接测序法对新疆南疆地区17例维吾尔族PKU患儿PAH基因第5外显子进行序列分析,以确定其突变位点。结果 34条染色体中检测到1种突变,即p.R158Q(c.473G>A),为错义突变;17例患儿中3例发生此突变,突变检出比例为17.65%。结论首次明确新疆南疆地区维吾尔族PKU患儿PAH基因第5外显子的突变种类和特征。 Objective To investigate the mutation of exon 5 of phenylalanine hydroxylase (PAH) gene in Uygur children with phenylketonuria (PKU) in southern Xinjiang. Methods The sequence analysis of PAH gene exon 5 in 17 cases of PKU in Xinjiang Uygur Autonomous Region was carried out by PCR direct sequencing to determine its mutation site. Results One mutation was detected in 34 chromosomes, p.R158Q (c.473G> A), which was a missense mutation. In the 17 cases, the mutation was detected in 3 cases and the mutation rate was 17.65%. Conclusions It is the first time to confirm the mutation types and characteristics of PAH gene exon 5 in Uighur PKU children in southern Xinjiang.