Association study of sepiapterin reductase gene promoter polymorphisms with schizophrenia in a Han Chinese population

Sepiapterin reductase participates in the biosynthesis of tetrahydrobiopterin, which plays very important roles in the pathogenesis of schizophrenia via dysregulation of neurotransmitter systems. Here, two single nucleotide polymorphisms (rs1876487 and rs2421095) in the promoter region of SPR were genotyped in 941 schizophrenic patients and 944 controls in a Han Chinese population using the SNaPshot technique. No significant differences were found in the distribution of alleles or genotypes of the two single nucleotide polymorphisms (SNPs) between schizophrenic patients and controls (all P>0.05). Likewise, no haplotype was found to be associated with schizophrenia. However, sex-stratified analysis revealed that the frequencies of the A allele of rs1876487 and the A-A (rs2421095-rs1876487) haplotype were all significantly different between schizophrenia and controls in females (P=0.040 and P=0.033, respectively), but not in males. Additionally, luciferase reporter gene assays revealed that the A-A haplotype had significantly higher SPR transcriptional activity compared with the A-C haplotype in SH-SY5Y cells. Our data indicate that the two SNPs do not influence the risk of schizophrenia when using the total sample, but the A allele of rs1876487 and the A-A haplotype may contribute to protective roles for schizophrenia in females.