title: Genetic characterisation of circulating fetal cells allows non-invasive prenatal diagnosis of cystic fibrosis.
abstract: OBJECTIVE
  Cystic fibrosis (CF) is an autosomal recessive disease due to mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The purpose of this study was to develop a molecular method to characterise both paternal and maternal CFTR alleles in DNA from circulating fetal cells (CFCs) isolated by ISET (isolation by size of epithelial tumour/trophoblastic cells).
  
  
  METHODS
  The molecular protocol was defined by developing the F508del mutation analysis and addressing it both to single trophoblastic cells, isolated by ISET and identified by short tandem repeats (STR) genotyping, and to pooled trophoblastic genomes, thus avoiding the risk of allele drop out (ADO). This protocol was validated in 100 leucocytes from F508del carriers and subsequently blindly applied to the blood (5 mL) of 12 pregnant women, at 11 to 13 weeks of gestation, whose offspring had a 1/4 risk of CF. Ten couples were carriers of F508del mutation, while two were carriers of unknown CFTR mutations.
  
  
  RESULTS
  Results showed that one fetus was affected, seven were heterozygous carriers of a CFTR mutation, and four were healthy homozygotes. These findings were consistent with those obtained by chorionic villus sampling (CVS).
  
  
  CONCLUSIONS
  Our data show that the ISET-CF approach affords reliable prenatal diagnosis (PND) of cystic fibrosis and is potentially applicable to pregnant women at risk of having an affected child, thus avoiding the risk of iatrogenic miscarriage.
authors.affiliation: INSERM, Unité 807, Paris, France, Université Réné Descartes, Paris, France.
authors.forename: Ali
authors.initials: A
authors.lastname: Saker
authors.forename: Alexandra
authors.initials: A
authors.lastname: Benachi
authors.forename: Jean Paul
authors.initials: JP
authors.lastname: Bonnefont
authors.forename: Arnold
authors.initials: A
authors.lastname: Munnich
authors.forename: Yves
authors.initials: Y
authors.lastname: Dumez
authors.forename: Bernard
authors.initials: B
authors.lastname: Lacour
authors.forename: Patrizia
authors.initials: P
authors.lastname: Paterlini-Brechot
mesh_terms: D000483:Alleles; D003550:Cystic Fibrosis / Q000175:diagnosis* / Q000235:genetics; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics*; D005260:Female; D005333:Fetus / Q000166:cytology*; D005820:Genetic Testing / Q000379:methods*; D006801:Humans; D009154:Mutation; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*
chemical_list: D019005:Cystic Fibrosis Transmembrane Conductance Regulator