REAL TIME AND REVERSE TRANSCRIPTASE POLYMERASE CHAIN REACTION MEASUREMENT OF MALE FETAL SRY GENE IN MATERNAL PLASMA WITH PREECLAMPSIA
Rokaya H. Shalaby and Rasha A. Abiya
Zoology Department, Women's College for Arts, Science, and Education, Ain Shams University
Preeclampsia (PE) occurs in about 7-10% of pregnancies .It is one of the reasons for death of women in procreation period in the world. The study was designed to determine if male fetal DNA is present in the maternal plasma circulation in third trimester pregnancy before the clinical manifestations of PE and if this could be predictive of the development of PE. Also, to clarify the relationship between fetal DNA levels and PE by using reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time quantitative (RT-qPCR) for SRY gene on the Y-chromosome, that quantifies a genetic marker specific in PE. Blood samples were obtained from fifty cases of pregnant women, 10 healthy pregnant women carrying male fetuses were recruited as a positive control, 10 healthy pregnant women carrying female fetuses used as a negative control and 30 pregnant women with preeclampsia were selected (gestation at 30 weeks). RNA and DNA was extracted from maternal plasma of peripheral blood and reverse transcriptase polymerase chain reaction (RT-PCR) was performed to determine fetal RNA (SRY). Also DNA was extracted and SRY levels in maternal plasma were quantified with a real-time quantitative polymerase chain reaction RT-qPCR. The obtained data revealed that the RT-PCR product of SRY gene appeared in the form of a signal fragment with molecular size 472 bp and band density (bd) 59.8±1.9 in preeclampsia versus 12.3±1.6 in positive control respectively. The SRY mRNA expression level was 23.1 in preeclampsia group vs 4.5 in positive control. The performance of RT qPCR revealed that the fetal DNA was increased fivefold in preeclampatic women more than the positive control. SRY levels were markedly higher by than those of the control group (154.3±73.2 copies/ml to 21.1±7.8, p < 0.05). These results suggested that increased SRY levels in maternal plasma may be a genetic marker specific in diagnosis of preeclampsia and predictive of the development of PE.