title: Preferential X-chromosome inactivation in women with idiopathic recurrent pregnancy loss.
abstract: OBJECTIVE
  To determine whether preferential X-chromosome inactivation (P-XCI) relates to idiopathic recurrent pregnancy loss.
  
  
  METHODS
  A retrospective study.
  
  
  METHODS
  Infertility clinics and laboratory.
  
  
  METHODS
  Women with idiopathic recurrent pregnancy loss (group I), women who had given birth to children but with no history of spontaneous abortion (group II), and women without a history of pregnancy (group III).
  
  
  METHODS
  DNA samples from the heterozygotes for the (CAG)n polymorphism within the androgen receptor gene were modified with sodium bisulfite, PCR-amplified with primer pairs for methylated androgen receptor alleles (M-PCR) and unmethylated alleles (U-PCR), and subjected to electrophoresis.
  
  
  METHODS
  Band peak patterns and peak area sizes.
  
  
  RESULTS
  In group I, 7 (16.7%) of 42 heterozygotes exhibited P-XCI; four possessed single-peak patterns in the M-PCR and U-PCR products, and three had two-peak patterns in which the peak sizes differed considerably. In group II, 2 (5.6%) of 36 heterozygotes exhibited P-XCI as determined by the two-peak patterns. In group III, none of the 47 heterozygotes exhibited P-XCI.
  
  
  CONCLUSIONS
  The incidence of P-XCI was statistically higher in group I than in the other groups. As P-XCI characterized by single-peak patterns was observed only in group I, such patterns, which may result from undiscovered cytogenetic or molecular abnormalities of the X-chromosome, likely correlate with pregnancy loss.
authors.affiliation: Department of Obstetrics and Gynecology, Tohoku University School of Medicine, Sendai, Japan. uehara@ob-gy.med.tohoku.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Uehara
authors.forename: M
authors.initials: M
authors.lastname: Hashiyada
authors.forename: K
authors.initials: K
authors.lastname: Sato
authors.forename: Y
authors.initials: Y
authors.lastname: Sato
authors.forename: K
authors.initials: K
authors.lastname: Fujimori
authors.forename: K
authors.initials: K
authors.lastname: Okamura
mesh_terms: D000026:Abortion, Habitual / Q000235:genetics*; D000328:Adult; D019175:DNA Methylation; D005260:Female; D006579:Heterozygote; D006801:Humans; D011110:Polymorphism, Genetic; D011247:Pregnancy; D011256:Pregnancy Outcome; D011944:Receptors, Androgen / Q000235:genetics; D012016:Reference Values; D014960:X Chromosome / Q000502:physiology*
chemical_list: D011944:Receptors, Androgen