P-222: Imprinted gene expression of placental tissue associated with neonatal weight and placental weight

Abstract

The incidence of epigenetic disorder diseases such as Beckwith-Wiedemann syndrome (BWS) is high in ART offspring. BWS is known as large offspring syndrome with a higher incidence of embryonic cancers. It is important to conclusively determine whether such epigenetic abnormalities are present in children conceived by ART. As a preriminally study, we examined the expression of imprinted genes in placental tissue from spontaneously conceived fetuses for getting the details of gene expression in the placental tissue of naturally conceived to compare ART offspring. Imprinted genes expressions of human placental tissues were assessed by real-time PCR. Placental tissues of spontaneously conceived cases were provided with informed consent under IRB protocol in our center. Total RNA was extracted from the fetal placenta and reverse transcription was performed. Gene expressions of IGF2, H19, KCNQ1OT1, and CDKN1C, were analyzed by Real-Time PCR with GAPDH serving as an endogenous control. A total of 69 patients provided placental tissue; deliveries took place from June 2005 to March 2006. The placentas of neonates with birth weights equal greater than 2500g but less than 3500g (group C: n = 44) were compared with those from neonates weights equal more than 3500g (group M: n =25). Average maternal age (33.3±45.2 vs. 31.8±4.9) and number of previous deliveries (0.4±0.8 vs. 0.7±0.9) did not significantly differ between groups. Placental weight (568.7±68.4g vs. 742.4±97.5g) was higher in group C than in group M. Although, the expressions of IGF2, KCNQ1OT1, and CDKN1C were similar, the expression of H19 was significantly higher in group M than in group C (p <0.01) We conferm that the expression of imprinted genes influences neonatal weight and placental weight even in spontaneously conceived infants.