title: Associations between androgen receptor CAG repeat length and sperm morphology.
abstract: BACKGROUND
  The number of (trinucleotide) CAG repeats within the androgen receptor (AR) gene is inversely correlated with transcriptional activity of testosterone-target genes. Although abnormally long CAG repeats are strongly associated with male infertility, it is unclear whether CAG repeat length polymorphism can affect androgen receptor activity and sperm parameters. To explore the previously suggested association between CAG repeats and male fertility, we conducted this prospective cohort study.
  
  
  METHODS
  We enrolled 172 men attending the IVF unit in Shaare-Zedek Medical Center. Sperm concentration, motility and morphology and the number of CAG repeats in the AR gene were measured.
  
  
  RESULTS
  Mean CAG repeat length was greater in teratozoospermia (<14% normal forms, strict criteria) than in the normal morphology group [mean +/- 95% confidence interval (CI) 22.19 +/- 0.38 versus 21.25 +/- 0.28, P = 0.02]. Logistic regression models showed that longer CAG repeats were associated with abnormal sperm morphology [odds ratio for percentage of normal forms per unit increase in CAG repeat length 1.14 (95% CI 1.01-1.28), P = 0.04]. No association was found between CAG repeat length and sperm concentration or motility.
  
  
  CONCLUSIONS
  We found a positive correlation between CAG repeat length and teratozoospermia. This finding validates the concept that AR function is inversely regulated by length of its CAG repeat tract.
authors.affiliation: IVF Unit, Shaare-Zedek Medical Center, Ben Gurion University of the Negev, Jerusalem 91031, Israel.
authors.forename: David
authors.initials: D
authors.lastname: Milatiner
authors.forename: David
authors.initials: D
authors.lastname: Halle
authors.forename: Michael
authors.initials: M
authors.lastname: Huerta
authors.forename: Ehud J
authors.initials: EJ
authors.lastname: Margalioth
authors.forename: Yoram
authors.initials: Y
authors.lastname: Cohen
authors.forename: Avraham
authors.initials: A
authors.lastname: Ben-Chetrit
authors.forename: Michael
authors.initials: M
authors.lastname: Gal
authors.forename: Tzvia
authors.initials: T
authors.lastname: Mimoni
authors.forename: Talia
authors.initials: T
authors.lastname: Eldar-Geva
mesh_terms: D000328:Adult; D015331:Cohort Studies; D006801:Humans; D007248:Infertility, Male / Q000235:genetics* / Q000473:pathology*; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D011446:Prospective Studies; D011944:Receptors, Androgen / Q000235:genetics*; D013076:Sperm Count; D013081:Sperm Motility; D013094:Spermatozoa / Q000002:abnormalities* / Q000473:pathology*; D018911:Trinucleotide Repeats / Q000235:genetics*
chemical_list: D011944:Receptors, Androgen