en زیست شناسی ملکولی Molecular Biology مقالات اصلی Original Article <div style="text-align: justify;"><strong><em>Background:</em></strong> Noninvasive fetal sex determination by analyzing Y chromosome-specific sequences is very useful in the management of cases related to sex-linked genetic diseases. The aim of this study was to establish a non-invasive fetal sex determination test using Real-Time PCR and specific probes.<br> <br> <strong><em>Methods:</em></strong> The study was a prospective observational cohort study conducted from August 2018 to September 2019. Venous blood samples were collected from 25 Iranian pregnant women at weeks 7 to 25 of gestation. Cell-free DNA (cfDNA) was isolated from the plasma of samples and fetal sex was determined by SRY gene analysis using the Real-Time PCR technique. In the absence of SRY detection, the presence of fetal DNA was investigated using cfDNA treated with BstUI enzyme and PCR for the epigenetic marker RASSF1A.<br> <br> <strong><em>Results:</em></strong> Of the total samples analyzed, 48% were male and 52% female. The RASSF1A assay performed on SRY negative cases also confirmed the presence of cell-free fetal DNA. Genotype results were in full agreement with neonate gender, and the accuracy of noninvasive fetal sex determination was 100%.<br> <br> <strong><em>Conclusions:</em></strong> Fetal sex determination using the strategy applied in this study is noninvasive and highly accurate and can be exploited in the management of sex-linked genetic diseases.</div> Cell-free fetal DNA, Fetal sex determination, Noninvasive prenatal diagnosis, Sex-linked genetic diseases, SRY. 315 323 http://rbmb.net/browse.php?a_code=A-10-478-1&slc_lang=en&sid=1 Mohammad Hossein Ahmadi 100319475328460017674 100319475328460017674 No Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran Naser Amirizadeh 100319475328460017675 100319475328460017675 No Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran Maryam Rabiee 100319475328460017676 100319475328460017676 No Department of Obstetrics and Gynecology, Shahed University, Tehran, Iran Fatemeh Rahimi-Sharbaf 100319475328460017677 100319475328460017677 No Department of Perinatology, Yas Hospital, Tehran University of Medical Sciences, Tehran, Iran Ali Akbar Pourfathollah pourfa@modares.ac.ir 100319475328460017678 100319475328460017678 Yes Department of Immunology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran