title: Androgenetic/biparental mosaicism causes placental mesenchymal dysplasia.
abstract: BACKGROUND
  Placental mesenchymal dysplasia (PMD) is a distinct syndrome of unknown aetiology that is associated with significant fetal morbidity and mortality. Intrauterine growth restriction is common, yet, paradoxically, many of the associated fetuses/newborns have been diagnosed with Beckwith-Wiedemann syndrome (BWS).
  
  
  METHODS
  We report two cases of PMD with high levels of androgenetic (complete paternal uniparental isodisomy) cells in the placenta and document, in one case, a likely androgenetic contribution to the fetus as well.
  
  
  RESULTS
  The same haploid paternal complement found in the androgenetic cells was present in coexisting biparental cells, suggesting origin from a single fertilisation event.
  
  
  CONCLUSIONS
  Preferential allocation of the normal cells into the trophoblast explains the absence of trophoblast overgrowth, a key feature of this syndrome. Interestingly, the distribution of androgenetic cells appears to differ from that reported for artificially created androgenetic mouse chimeras. Androgenetic mosaicism for the first time provides an aetiology for PMD, and may be a novel mechanism for BWS and unexplained intrauterine growth restriction.
authors.forename: K A
authors.initials: KA
authors.lastname: Kaiser-Rogers
authors.forename: D E
authors.initials: DE
authors.lastname: McFadden
authors.forename: C A
authors.initials: CA
authors.lastname: Livasy
authors.forename: J
authors.initials: J
authors.lastname: Dansereau
authors.forename: R
authors.initials: R
authors.lastname: Jiang
authors.forename: J F
authors.initials: JF
authors.lastname: Knops
authors.forename: L
authors.initials: L
authors.lastname: Lefebvre
authors.forename: K W
authors.initials: KW
authors.lastname: Rao
authors.forename: W P
authors.initials: WP
authors.lastname: Robinson
mesh_terms: D000328:Adult; D000728:Androgens / Q000378:metabolism; D005260:Female; D005838:Genotype; D006801:Humans; D007621:Karyotyping; D008648:Mesoderm / Q000473:pathology*; D018895:Microsatellite Repeats / Q000235:genetics; D009030:Mosaicism; D010922:Placenta Diseases / Q000235:genetics* / Q000473:pathology*; D011247:Pregnancy
chemical_list: D000728:Androgens