ABSTRACT
Objective@#To explore the spectrum of genetic variants among patients with hyperphenylalaninemia (HPA) from Quanzhou area of Fujian province.@*Methods@#For 63 children affected with HPA, next generation sequencing was used to identify potential variants in PAH, PTS, PCBD1, QDPR, SPR and GCH1 genes.@*Results@#Fifty two variants underlying phenylalanine hydroxylase deficiency (PAHD) and 13 variants underlying 6-pyruvoyl tetrahydropterin synthase deficiency (PTPSD) were identified. Two patients carried variants of both PAH and PTS genes. The most common variants of the PAH gene were R53H (21.69%), R241C (18.07%), R243Q (12.05%) and EX6-96A>G (7.23%), which were mainly located in exons 7 (32.53%), 2 (21.69%), 6 (9.64%) and 12 (9.64%). The L227M variant of the PAH gene was unreported previously. N52S (35.00%), P87S (25.00%), IVS1-291A>G (10.00%) and T67M (10.00%) variants were the most common variants for the PTS gene and were mainly located in exons 2 (35.00%) and 5 (35.00%).@*Conclusion@#The variant spectrum underlying HPA in Quanzhou area showed a geographical specificity. A novel variant of the PAH gene (L227M) has been detected.
ABSTRACT
Objective To study the effects of sodium arsenite on the mRNA expression of GTP cyclohydrolase (GTPCH) and 6-pyruvoyl-tetrahydropterin synthase (PTPS) in Chang liver cells. Methods Human Chang liver cells were cultured with sodium arsenite at doses of 0, 50, 200 and 400 ?mol/L for 12 hours. Cell viability was tested by MTT assay, and the expression of mRNA of GTPCH and PTPS was detected by RT-PCR. Results Cell viability in 50 ?mol/L group was almost the same as that in control, while the viability in the other two groups were significantly lower than that in control. All of the mRNA expression levels in the three groups were significantly lower than that in control with dose-dependent manner. Conclusion The down-regulated expression of GTPCH and PTPS, the main enzymes of the synthesis of BH4, induced by sodium arsenite exposure may be related with arsenic related skin depigmentation.