Abstract: Objective To explore the feasibility of detecting of Y-STR of fetal DNA in maternal plasma using Ion Torrent PGMTM System. Methods A total of 16 fetal DNA samples from maternal plasmas （8 cases from 38 weeks gestational age and 8 ones from 12 weeks） were prepared and a multiplex assay with 7 STR loci （DYS390, DYS391, DYS393, DYS438, DYS437, DYS456, DYS635） was designed for multiplex-PCR amplification. Using Ion Torrent PGMTM System, the results of Y-STR sequences and capillary electrophoresis were obtained and compared. Results Y-STR specific alleles were detected in the maternal plasma of all the pregnant women having male babies of second and third trimester, which were higher than that detected by capillary electrophoresis. Consistent Y-STR genotypes were observed between fetal DNA from maternal plasma and genomic DNA from the newborn babies. Conclusion Based on Ion Torrent PGMTM System, the prenatal Y-STR detection method may provide a high-sensitive and high-throughput choice for prenatal STR detection in forensic testing.

Key words: forensic genetics, Y chromosome, pregnant women, fetus, short tandem repeat sequences, Ion Torrent PGMTM System