Prenatal Screening Using QF-PCR and Karyotyping with an Evaluation of Short Tandem Repeats Markers in the Iranian Population

Quantitative fluorescent Polymerase Chain Reaction (QF-PCR) has been widely used by laboratories as a rapid, low-cost, and convenient test compared to conventional karyotyping for detecting the most common aneuploidies for prenatal diagnosis. Although the latter has been considered the gold standard for detection, the debate to use QF-PCR or both methods together continues. We screened the results of QF-PCR and karyotyping to compare their detection rate for the most common aneuploidies. In addition, we aimed to investigate the most informative markers in the Iranian population for aneuploidies.  We screened 741 pregnant women’s amniotic fluid samples with nuchal translucency (NT) ≥2.5 for two years, during which QF-PCR and karyotyping were performed to compare the results. Also, we did a statistical assessment of samples for heterozygosity of 25 short tandem repeats (STR) markers in the Iranian population, which can be applied to find the most informative markers based on the population for each chromosome analyzed in the QF-PCR test. The QF-PCR results were 99.8, consistent with the results of cytogenetic analysis, and just one case could not be detected with QF-PCR due to mosaicism.  Among the evaluated markers in this study, D13S258, D18S51, and D21S1411 had the highest frequency of heterozygosity. QF-PCR could be used as a stand-alone test to reduce the workload and time-consuming of karyotyping, but using both of them could lead us to the most reliable results.