title: Could androgen receptor gene CAG tract polymorphism affect spermatogenesis in men with idiopathic infertility?
abstract: OBJECTIVE
  This study examined whether the AR-CAG repeat length might affect clinical characteristics (testis volume) seminal parameters (sperm count and its mobility) along with hormonal serum profile [FSH, LH, Testosterone (T) and Inhibin B (InhB)] both in idiopathic male infertility (IM) and in infertility due to a previous condition of cryptorchidism (CryM) or to Y chromosome long arm microdeletions (YM).
  
  
  METHODS
  Observational study without intervention(s).
  
  
  METHODS
  One hundred and ten IM patients [90 idiopathic olizoospermic males (IOM) and 20 idiopathic azoospermic males (IAM)], 19 CryM male and 10 YM patients were included. Sixty-one age-matched healthy men who had fathered within 3 years were involved representing the control group (FM).
  
  
  RESULTS
  AR-CAG repeats stretch was significantly longer in IOM (p<0.05), CryM (p<0.05) and YM (p<0.001) than FM. When the AR-CAG repeat tracts were subdivided in three subgroups according to the length of CAG repeats tract assessed in fertile subjects (the one with the middle (n 19-21) belonging to the 25 and 75 % inter-quartile, the ends belonging to the <25 % inter-quartile and >75 % inter-quartile, respectively), there was a statistically significant difference of distribution of AR-CAG tract length among fertile and different groups of infertile men (p=<0.0005; chi-square test). Moreover, the subgroup of AR-CAG repeat stretch with 22-28 triplets was associated with lower levels of InhB both in idiopathic oligozoospermic (Scheffe, Bonferroni and Dunett tests p=<0.01) and azoospermic men (Scheffe, Bonferroni and Dunett test p=<0.05), while, when FM and men with idiopathic infertility were gathered in a single group, both the subgroup of AR- CAG tract with 15-18 repeats and the one with 22-28 repeats are associated with lower testis volume, reduced sperm count and serum InhB levels.
  
  
  CONCLUSIONS
  Our study showed that the outliers of AR-CAG repeat length seem to influence the function of AR, affecting testis volume and Sertoli cell function and consequently sperm production in both fertile and idiopathic infertile men.
authors.affiliation: Endocrinology and Metabolic Diseases, University of Bari, Bari, Italy, vitogiagulli@alice.it.
authors.forename: V A
authors.initials: VA
authors.lastname: Giagulli
authors.forename: M D
authors.initials: MD
authors.lastname: Carbone
authors.forename: G
authors.initials: G
authors.lastname: De Pergola
authors.forename: E
authors.initials: E
authors.lastname: Guastamacchia
authors.forename: F
authors.initials: F
authors.lastname: Resta
authors.forename: B
authors.initials: B
authors.lastname: Licchelli
authors.forename: C
authors.initials: C
authors.lastname: Sabbà
authors.forename: V
authors.initials: V
authors.lastname: Triggiani
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D008875:Middle Aged; D002872:Chromosome Deletion; D041322:Chromosomes, Human, Y / Q000235:genetics; D003456:Cryptorchidism; D007248:Infertility, Male / Q000235:genetics; D009845:Oligospermia / Q000235:genetics / Q000473:pathology; D011944:Receptors, Androgen / Q000235:genetics; D012729:Sex Chromosome Aberrations; D058533:Sex Chromosome Disorders of Sex Development / Q000235:genetics / Q000473:pathology; D013076:Sperm Count; D013081:Sperm Motility; D013091:Spermatogenesis / Q000235:genetics; D018911:Trinucleotide Repeats / Q000235:genetics
chemical_list: D011944:Receptors, Androgen