title: Fetal-specific hypermethylated RASSF1A quantification in pregnancy.
abstract: OBJECTIVE
  To quantify cell free fetal DNA (cffDNA) with fetal specific epigenetic marker, hypermethylated RASSF1A, in maternal plasma of normal pregnant women from 20 weeks of gestation and to assess its relationship with maternal age, height, pre-pregnancy weight and body mass index (BMI).
  
  
  METHODS
  Hundred normal pregnant women within the gestational age of 21-40 weeks were randomly selected and grouped into five (n = 20). Group 1: 21-24, Group 2: 25-28, Group 3: 29-32, Group 4: 33-36 and Group 5: 37-40 weeks. Maternal plasma DNA was extracted, digested with methylation-sensitive restriction enzyme, BstUI and the fetal specific DNA (cffDNA) was quantified by Real-time polymerase chain reaction (qRT-PCR).
  
  
  RESULTS
  The mean hypermethylated RASSF1A concentrations in different gestational groups were Group 1: 30.1 ± 14.9, Group 2: 52.6 ± 22.18, Group 3: 93.2 ± 19.08, Group 4: 172.8 ± 26.81 and Group 5: 337.8 ± 52.9 copies/ml. Pearson's correlation analysis showed highly significant positive correlation between cffDNA and gestational age (r = 0.899, p < 0.001). BMI was also found to be positively related to cffDNA (r = 0.217, p < 0.05). However, it did not show any correlation with maternal age, height and pre-pregnancy weight.
  
  
  CONCLUSIONS
  The gestational age-dependent increase of hypermethylated RASSF1A; the fetal specific epigenetic marker in maternal plasma was demonstrated, in an Indian study group of normal pregnant women. Findings would form the basis of future studies involving pregnancy complications that would aid in the early diagnosis of placental pathologies with hypermethylated RASSF1A.
authors.affiliation: a Base Hospital, Delhi Cantt, School of Medicine & Paramedical Health Sciences, Guru Gobind Singh Indraprastha University , Delhi , India.
authors.forename: Seema
authors.initials: S
authors.lastname: Saraswathy
authors.affiliation: b Department of Pathology , Armed Forces Medical College (AFMC) , Pune , India.
authors.forename: Kavita
authors.initials: K
authors.lastname: Sahai
authors.affiliation: c Department of Obstetrics and Gynecology , Base Hospital and Army College of Medical Sciences (ACMS) , Delhi Cantt , India.
authors.forename: Devendra
authors.initials: D
authors.lastname: Arora
authors.affiliation: d Institute of Nuclear Medicine & Allied Sciences (INMAS), Defence Research & Development Organization(DRDO), Ministry of Defence, Govt. of India , Delhi , India.
authors.forename: Manu
authors.initials: M
authors.lastname: Krishnan
authors.affiliation: e North DMC Medical College, Hindu Rao Hospital , Delhi , India.
authors.forename: Suman Lata
authors.initials: SL
authors.lastname: Mendiratta
authors.affiliation: f Department of Biosciences , Jamia Millia Islamia , Delhi , India , and.
authors.forename: Shilpie
authors.initials: S
authors.lastname: Biswas
authors.affiliation: g Department of Zoology , Mar Thoma College , Tiruvalla , Kerala , India.
authors.forename: Kurian Mathew
authors.initials: KM
authors.lastname: Abraham
mesh_terms: D000328:Adult; D019175:DNA Methylation; D005260:Female; D005333:Fetus / Q000378:metabolism*; D005865:Gestational Age; D006801:Humans; D007194:India; D008423:Maternal Age; D011247:Pregnancy; D011248:Pregnancy Complications / Q000235:genetics; D011296:Prenatal Diagnosis / Q000379:methods; D025521:Tumor Suppressor Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: C411762:RASSF1 protein, human; D025521:Tumor Suppressor Proteins
keywords: cffDNA; epigenetic marker; hypermethylated RASSF1A