Application of MiniSTR in the detection of fetal DNA in maternal plasma / 中国输血杂志

ABSTRACT

Objective To develop an efficient method for detecting the short tandem repeat(STR) of fetal DNA in maternal plasma by miniSTR technique.Methods A total of 9 blood samples form pregnant women from 11 to 27 weeks of gestation were collected.Each isolated total plasma DNA was amplified in single multiplex using the ABI MiniFilerTM kit,which could simultaneously genotype the 9 miniSTR loci,including D13S317,D7S820,D2S1338,D21S11,D16S539,D18S51,CSFIPO,FGA and Amelogenin,and the PCR products were detected by using ABI PrismTM 3100 DNA Sequencer.The allelic designation of each STR locus was accomplished using the GeneMapper ID 3.2 software.Results Father-origin fetal STR allele was detected in all the 9 plasma DNA samples.An average of 3.1 fetal STR alleles of the 8 autosomal STR loci was observed in each of the 9 plasma DNA samples.As for the Amelogenin locus,Amelogenin Y allele was detected in 5 plasma DNA samples from pregnancies with male fetus,and allelic peak height values were all over 50 RFU,according to ABI Mini FilerTM PCR conditions,and the ratio of Amelogenin Y allele peak height value to Amelogenin X allele peak height value was 8.45%.However,no Amelogenin Y allele was detected in other 4 plasma DNA samples from pregnant women with female fetus.Conclusion The miniSTR technique is suitable for STR genotyping using fetal DNA in maternal plasma,and it suggests a broad application in noninvasive molecular prenatal diagnosis.