Risk Of IL-17F Polymorphisms With Tourette Syndrome In A Chinese Han Population

Objective Tourette syndrome(TS)is a childhood onset chronic neuropsychiatric disorder characterized by multiple motor and one or more vocal tics and accompanied by various complications.The pathogenesis is not fully clear.In this study,we investigated the association between functional polymorphisms in IL-17 F and TS genetic susceptibility in a Chinese Han population.Methods We recruited 407 TS nuclear family trios(325 male cases and 82 female cases each with their parents)and 417 controls(321 male and 96 female),and performed Taq Man allelic discrimination real–time PCR to genotype two single nucleotide polymorphisms(SNP)in IL-17 F,rs1889570 and rs763780.The transmission disequilibrium test(TDT)and haplotype relative risk(HRR)were used to estimate genetic susceptibility.In addition,we designed a classic case–control study to identify differences in the genetic distributions of these polymorphisms.All of the statistical significance was set at p<0.05.Results No transmission disequilibrium was found between the IL-17 F tag polymorphisms rs1889570 and rs763780 and TS in the family–based study(rs1889570:p TDT =0.266,p HRR=0.051;rs763780:pTDT=0.092,p HRR=0.083).The allelic frequencies and genotypic distributions were compared by Pearson's chi–square test,which also indicated there was no remarkable difference between the TS patients and the controls(rs1889570 : pgenotypic distributions=0.188,pallelic frequencies=0.211;rs763780 : pgenotypic distributions=0.105,pallelic frequencies=0.555).Conclusion The results of family–based analysis and classical case–control analysis indicated that the genetic variants of rs763780 and rs1889570 in IL-17 F may not play a crucial role in the pathogenesis of TS in a Chinese Han population.In addition,we note that the results of TDT and HRR test(p value)of the rs763780 site are closer to the critical value,so increasing the sample size is the next work to be done.At the same time,to determine whether there is a racial difference in genetic susceptibility,the study should be confirmed in other geographic and ethnic populations.