RESUMEN
<p><b>OBJECTIVE</b>To determine the gene mutation spectrum of patients with 6-pyruvoyltetrahydrobiopterin synthesis deficiency (PTPSD) in Mainland China.</p><p><b>METHODS</b>The 6-pyruvoyltetrahydrobiopterin synthesis gene lz(PTS)lz was analyzed in 55 PTPSD patients by using PCR-restriction fragment length polymorphism (PCR-RFLP) and direct DNA sequencing. The relationship between the genotype and phenotype was analyzed.</p><p><b>RESULTS</b>Eighteen mutations were identified and the detection rate of gene mutation was 95.28%. Four hot-spot mutations, namely P87S (40.57%), N52S(13.21%), D96N(12.26%) and IVS1nt-291A to G(10.38%) were found in this study, and the first three were associated with severe phenotype. The P87L was reported firstly in Chinese patients, and the Q13X, M80T, IVS4nt-2A to G, L93M and K131N were novel mutations.</p><p><b>CONCLUSION</b>The P87S, N52S, D96N and IVS1nt-291A to G mutations are the hot-spots mutations of the PTS gene in Chinese PTPSD patients. Using PCR-RFLP technique to screen the mutations in the PTS gene can increase the efficiency of gene diagnosis.</p>