RESUMEN
<p><b>OBJECTIVE</b>To study the characteristics of the phenylalanine hydroxylase gene (PAH) mutations in patients with phenylketonuria (PKU) in Henan province, in order to provide basic information for genetic counseling and prenatal diagnosis.</p><p><b>METHODS</b>Mutations of the PAH gene were detected in exons 1-13 with flanking introns of PAH gene by PCR and DNA sequencing in 47 families with PKU.</p><p><b>RESULTS</b>A total of 25 different mutations were detected in 83 out of 94 PAH alleles (88.3%). Among them, E79fX13, H271R and D415Y have not been reported previously. It was the first time that IVS10-14C to G mutation was reported in Chinese PKU population. The mutations p.R243Q, EX6-96A to G, p.Y356X, IVS401G to A, p.R111X, p.V399V and p.R413P, were the prevalent mutations with relative frequencies of 20.5%, 12.0%, 9.6%, 9.6%, 8.4%, 8.4% and 7.2% respectively.</p><p><b>CONCLUSION</b>The mutations of the PAH gene in patients with classical phenylketonuria in Henan province were similar to that in other areas of China. Prenatal gene diagnosis for PKU by PAH gene sequencing is efficient for most PKU families.</p>