title: Beckwith Wiedemann imprinting defect found in leucocyte but not buccal DNA in a child born small for gestational age.
abstract: BACKGROUND
  Loss of methylation (LOM) at imprinting control region (ICR) 1 or LOM at ICR 2 on chromosome 11p15 in leucocyte DNA is commonly used to diagnose the imprinting disorders Silver Russell syndrome (SRS) characterized by growth restriction or Beckwith Wiedemann syndrome (BWS) characterized by overgrowth, respectively.
  
  
  METHODS
  A child was normally conceived and born by caesarian section to a healthy 19 year old smoking mother (G2P1) at 38 weeks gestation, with SGA (birthweight SDS -2.44), placenta weight 250g (normal histology), with an umbilical hernia and transient neonatal hypoglycemia but no other features of BWS.The methylation status at 11p15 region was initially investigated by multiplex ligation dependent probe amplification (MLPA). Subsequently, methylation-specific (ms) PCR was performed to screen for this and other imprinted loci abnormalities at PLAG1 (6q24), IGF2R (6q27), GRB10 (7p12), PEG1/MEST (7q32), DLK1 (14q32), SNRPN (15q11); PEG3 (19q32), NESPAS/GNAS (20q13).Leucocyte DNA methylation was normal at ICR1 but markedly reduced at ICR2 using both MLPA and ms-PCR, and no other anomalies of imprinting were detected. Buccal DNA methylation was normal at all imprinted sites tested.
  
  
  CONCLUSIONS
  This is the first report of an isolated LOM at ICR2 in leucocyte but not buccal DNA in a normally conceived singleton SGA child without overt SRS or BWS.
authors.affiliation: Department of Medicine, FMHS, University of Auckland, Auckland, New Zealand. R.Murphy@auckland.ac.nz
authors.forename: Rinki
authors.initials: R
authors.lastname: Murphy
authors.forename: Deborah
authors.initials: D
authors.lastname: Mackay
authors.forename: Ed A
authors.initials: EA
authors.lastname: Mitchell
mesh_terms: D000293:Adolescent; D001506:Beckwith-Wiedemann Syndrome / Q000175:diagnosis / Q000235:genetics*; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics; D004247:DNA / Q000235:genetics; D019175:DNA Methylation / Q000235:genetics; D005260:Female; D018392:Genomic Imprinting; D006554:Hernia, Umbilical / Q000175:diagnosis / Q000235:genetics; D006801:Humans; D007003:Hypoglycemia / Q000175:diagnosis / Q000235:genetics; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D007962:Leukocytes; D009061:Mouth Mucosa; D056730:Silver-Russell Syndrome / Q000175:diagnosis / Q000235:genetics
chemical_list: D004247:DNA