Genotype of Mild 6-pyruvoyl-tetrahydropterin Synthase Deficiency: Three Case Reports and a Literature Review

摘要

Objectives: To analyse the characteristics of mutation in PTS gene in Chinese patients with mild 6-pyruvoyl-tetrahydropterin synthase deficiency (M-PTSD). Methodology: Clinical and genetic data of three newborns with M-PTSD were collected from the Newborn Screening Center of Zhejiang Province, China. The characteristics of gene mutation in the selected patients were analysed together with local and international literature related to PTS gene and M-PTSD. Results: Nine M-PTSD patients have been reported in China, including three with the IVS1-291A>G/D96N genotype, two with the L93M/ N52S genotype, and one each with the IVS1-291A>G/N52S, IVS1-291A>G/L127F, V56M/R25G, and V56M/T106M genotypes. Four M-PTSD patients have been reported abroad: one each with the genotypes IVS1-322A>T/IVS1-322A>T, L26F/V124L, N47D/D116G, and R16C/C370_383 (K120→stop). Conclusion: Results showed ethnic differences in the M-PTSD related mutations. In the Chinese population, IVS1-291A>G, L93M, and V56M are mild-type mutations, and IVS1-291A>G is the most common benign mutation (27.8%). M-PTSD is not rare among individuals from mainland China, and newborns screened with PTSD should undergo mutation detection as soon as possible in order for physicians to select the appropriate therapeutic regimen and avoid over-treatment.