A Pilot Study Of Noninvasive Prenatal Paternity Tesing Based On STR And SNP Typing

Current prenatal paternity testing depends on invasive sampling in order to obtain the fetal DNA information.Besides,this method has limited sampling time and carries a certain risk of miscarriage.However,it is necessary to develop a noninvasive prenatal paternity testing method especially in rape with pregnant cases.This study used STR and SNP typing in maternal plasma in order to evaluate the possibility of noninvasive prenatal paternity testing.The study contained three main parts as following:1.Feasibility study of conventional STR typing technique for noninvasive prenatal paternity testing According to the current research results,combining with the characteristics of fetal DNA in maternal plasma,ampFLSTR MiniFilerTM and ampFLSTR yfiler kit was used to perform STR typing in maternal plasma.This part of study explored the feasibility of traditional STR typing technique for noninvasive prenatal paternity testing.2.Feasibility study of STR typing based on Next Generation sequencing technology for noninvasive prenatal paternity testingAccording to the current research results,combining with the characteristics of fetal DNA in maternal plasma,six chromosome STR loci,six Y chromosome STR loci and a sex determination loci were chosed to perform STR typing.All the primers of ablove loci were below 200bp.When the primers meet the quality criteria,all the samples performed mulityplex amplified and obtaine the final sequencing library based on WafGen platform.The sequencing data was obtained from Ion PGM 400 sequencing platform.This part of studt is in order to evaluate the feasibility of STR typing based on Next Generaton Seqeucing for noninvasive prenatal paternity testing.3.Feasibility study of SNP typing based on target capture sequencing technology for non invasive prenatal paternity testingThis part of the study used one family(mother of whole blood DNA,maternal plasma DNA,father of whole blood DNA and fetal amniotic fluid DNA)to perform whole genome sequencing(WGS),and developed a noninvasive prenatal paternity testing system based on high-throughput sequencing of SNP genotyping technology.Meanwhile serveal factors were perfomed evaluated including SNP minor allele frequency(MAF),plasma effective number of sites,sequencing depth and fetal concentrations,and established the initial quality control standards of the detection system.This part of studt is in order to evaluate the feasibility of SNP typing based on Next Generaton Seqeucing for noninvasive prenatal paternity testing.