The Pathogenic Gene Study Of A Family With Hashimoto's Thyroiditis And The Association Analysis Of SNP Rs12532, Rs870142 And The Risk Of Congenital Heart Disease In Tibetans

Background:Hashimoto’s thyroiditis（HT）is a complex autoimmune thyroid disease,the onset of which is associated with environmental exposures and specific susceptibility genes.The incidence of female in this disease is higher than that of male.Thus far,although some susceptibility loci have been elaborated in previous studies,including PTPN22,FOXP3,and CD25,the aetiology and pathogenesis of Hashimoto’s thyroiditis remains unclear.Methods:We collected a family of three generations with HT,of which six members were affected and all females.The peripheral blood samples from proband and her three affected relatives were selected for Whole-Exome Sequencing（WES）.The sequencing results were tested and screened according to the strict criteria designed to identify the pathogenic gene mutation of the family.Sanger sequencing was performed on all peripheral blood samples that had been collected in the family to validate candidate pathogenic genes and mutations,and the associated proteins were subjected to a hazard analysis via online websites.Results:After WES and bioinformatics analysis,we identified a rare missense mutation in the PTPN22 gene（NM₀15967.5;c.77A>G;p.Asn26Ser）.PTPN22 is a susceptibility gene for this disease and is associated with the development of a variety of autoimmune diseases.All public databases show that this missense mutation is extremely rare.Sanger sequencing showed that all female patients in this family carried the mutation.The conservative analysis showed that the site is more conserved in the protein,and the mutation results in an increase in the amino acid hydrophobicity of the site.Conclusion:This is the first time that the missense mutation PTPN22 A77G was found in HT family patients in this study.This further demonstrates the pathogenic or susceptibility of PTPN22 in autoimmune thyroid disease,providing a new direction for the genetic pathogenesis of the disease.Background:Congenital heart disease（CHD）is a disease in which the structure or function of the heart is abnormal during the fetal period,with high morbidity and mortality.Qinghai-Tibet Plateau is one of the most extreme areas of human living environment.The incidence of CHD in this area is more severe than in plain area.In the previous GWAS study,TBX1,NKX2.5,GATA4 and MSX1 genes were all associated with the occurrence of CHD.The SNPs rs12532 and rs870142 in MSX1 gene may be related to CHD.Because the incidence and cause of CHD may vary with different race and region,the correlation between rs12532 and rs870142 and the risk of Tibetan CHD remains unknown.Methods:We collected blood samples and clinical data from 387 Tibetan congenital heart disease patients and randomly selected 690 general population samples as controls.We performed matrix-assisted laser desorption/ionization time-of-flight mass spectrometry experiments for genotypic analysis Statistical analysis was performed with IBM SPSS Statistics 22.0.Significant differences between or among groups were indicated by values of P<0.025.Results:Among the SNP rs12532 loci,we found significant differences in genotype frequencies comparing cases and controls（P<0.05）,and the recessive model（GG/AA+AG）increased the risk of CHD（OR=1.680,P=0.005）in the rs12532 locus.At the same time,there was a statistically significant difference in genotype frequency distribution between the ASD subtypes and the control group.In the analysis of SNP rs870142 locus,all results showed that there were no significant differences between the case and control group.After gender correction,all results did not change.There was no significant association between either haplotype and CHD disease in the detection of haplotypes.Conclusion:Our results suggest that rs12532 may be associated with the development of CHD in the plateau,whereas rs870142 does not have the relationship with the disease.This result provides a new idea for the future study of susceptible sites in high altitude CHD.