Detection of the prevalent mutations of 6-pyruvoyl-tetrahydropterin synthase gene by PCR-RFLP analysis in Chinese patients

Objective: To establish a single and rapid method for detecting the prevalent mutations of 6-pyruvoyl-tetrahydropterin synthase (PTPS) gene in Chinese patients with 6-pyruvoyl-tetrahydropterin synthase deficiency (PTPSD).

Methods: PCR-restriction fragment length polymorphism (PCR-RFLP) was used to detect three prevalent PTPS gene mutations in 4 cases of tetrahydrobiopterin deficiency (BH4D) and their parents, which was performed by the artificial construct restriction site (ACRS). PCR-RFLP included Hpa I digestion for the detection of mutation N52S (155A to G), Hae III for P87S (259C to T) and Eco R I for D96N(286G to A). The mutations of PTPS gene were confirmed by direct sequencing.

Results: The genotypes of 4 PTPS deficient patients were identified: N52S/-, P87S/D96N, N52S/D96N and D96N/-. The result of direct sequencing was coincident with that of PCR-RFLP analysis.

Conclusions: (1) The PCR-RFLP analysis formed by ACRS would be a good way for detecting the three prevalent PTPS gene mutations in Chinese patients with PTPSD. (2)The PTPS gene analysis is very important for all patients with hyperphenylalaninemia, which would be useful for early clinical diagnosis and correct treatment of BH4D patients.