title: Sex chromosome characteristics and recurrent miscarriage.
abstract: OBJECTIVE
  To investigate whether skewed X chromosome inactivation (XCI) and Y chromosome microdeletions are associated with recurrent miscarrige (RM).
  
  
  METHODS
  A retrospective study.
  
  
  METHODS
  University hospital and genetic laboratory.
  
  
  METHODS
  Altogether, 46 women with a history of RM, defined as at least three miscarriages, and a control group of 95 women with no history of miscarriage were included in the XCI study. In the Y chromosome microdeletion study 40 male partners of women with RM were studied.
  
  
  METHODS
  Blood samples for DNA extraction.
  
  
  METHODS
  X chromosome inactivation patterns in the females were analyzed using a methylation-sensitive assay. The DNA from males was tested for Y chromosome microdeletions by analyzing 37 sequence tagged sites.
  
  
  RESULTS
  Mildly skewed XCI (>85% inactivation of one allele) was detected in 4 of 43 (9.3%) patients, and 9 of 81 (11.1%) controls. Among these women, extremely skewed XCI (>90% inactivation of one allele) was detected in 2 of 43 (4.7%) patients, and 4 of 81 (4.9%) controls. No statistical differences could be shown between the groups. No microdeletions were found in the male partners.
  
  
  CONCLUSIONS
  The frequency of both extremely and mildly skewed XCI was similar in patients and control women. Y chromosome microdeletions were not found in spouses of patients. Based on these results we conclude that skewed X inactivation and Y chromosome microdeletions are not associated with RM in our study couples.
authors.affiliation: Folkhälsan Institute of Genetics, University of Helsinki, Helsinki, Finland. milja.kaare@helsinki.fi
authors.forename: Milja
authors.initials: M
authors.lastname: Kaare
authors.forename: Jodie N
authors.initials: JN
authors.lastname: Painter
authors.forename: Veli-Matti
authors.initials: VM
authors.lastname: Ulander
authors.forename: Risto
authors.initials: R
authors.lastname: Kaaja
authors.forename: Kristiina
authors.initials: K
authors.lastname: Aittomäki
mesh_terms: D000026:Abortion, Habitual / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D041321:Chromosomes, Human, X; D041322:Chromosomes, Human, Y; D005260:Female; D005387:Finland; D017353:Gene Deletion; D020868:Gene Silencing; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D011247:Pregnancy; D012189:Retrospective Studies; D016324:Sequence Tagged Sites; D055815:Young Adult