title: Defects in imprinting and genome-wide DNA methylation are not common in the in vitro fertilization population.
abstract: OBJECTIVE
  To examine an IVF cohort for imprinted and genome-wide DNA methylation abnormalities.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  Research laboratory.
  
  
  METHODS
  DNA samples from a previously described IVF cohort that comprised 66 IVF-conceived prepubertal children (IVF, n = 34; intracytoplasmic sperm injection, n = 32) and 69 matched naturally conceived controls.
  
  
  METHODS
  DNA methylation was examined at four imprinted gene loci (H19, SNRPN, KCNQ1OT1, and IGF2) and satellite 2 using methylation-sensitive quantitative polymerase chain reaction (MSQ-PCR) followed by bisulfite sequencing at H19, SNRPN, and KCNQ1OT1. Methylated DNA immunoprecipitation (MeDIP) microarray with validation using the Sequenom MassARRAY EpiTYPER(®) platform was also used.
  
  
  METHODS
  Percentage of DNA methylation by MSQ-PCR, differential methylation based on microarray signal intensity, and percentage DNA methylation as determined by Sequenom MassARRAY EpiTYPER were compared.
  
  
  RESULTS
  No differences in percentage of methylation between the IVF and control group were observed at H19, KCNQ1OT1, SNRPN, or IGF2. Absence of aberrant imprinting was confirmed using bisulfite sequencing. Methylation of satellite 2 repeats (a surrogate for global methylation) showed no difference between the IVF and control groups. MeDIP was used to screen for differences in promoter methylation. Subsequent quantification of methylation of eight candidate genes using the Sequenom MassARRAY EpiTYPER system did not reveal any differential methylation.
  
  
  CONCLUSIONS
  Low-level imprinting errors are not common in the IVF population.
authors: Cancer Genetics Laboratory, Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors: Verity F
authors: VF
authors: Oliver
authors: Harriet L
authors: HL
authors: Miles
authors: Wayne S
authors: WS
authors: Cutfield
authors: Paul L
authors: PL
authors: Hofman
authors: Jackie L
authors: JL
authors: Ludgate
authors: Ian M
authors: IM
authors: Morison
mesh_terms: D002648:Child; D019175:DNA Methylation / Q000235:genetics*; D046149:Embryo Culture Techniques / Q000706:statistics & numerical data; D005260:Female; D005307:Fertilization in Vitro / Q000706:statistics & numerical data*; D030342:Genetic Diseases, Inborn / Q000453:epidemiology / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000453:epidemiology / Q000235:genetics; D055106:Genome-Wide Association Study; D018392:Genomic Imprinting / Q000235:genetics*; D006801:Humans; D007246:Infertility / Q000453:epidemiology / Q000235:genetics* / Q000628:therapy; D008297:Male; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology*; D012189:Retrospective Studies; D020554:Sperm Injections, Intracytoplasmic / Q000706:statistics & numerical data