title: Androgen receptor gene CAG and GGC repeat lengths in cryptorchidism.
abstract: OBJECTIVE
  Cryptorchidism is the most common congenital birth defect in male children, and accumulating evidence suggests that genetic abnormalities may be associated with it. The androgen receptor has two polymorphic sites in exon 1, with different numbers of CAG and GGC repeats, resulting in variable lengths of polyglutamine and polyglycine stretches. Longer CAG repeats result in a reduced androgen receptor transcriptional activity, but the role of the GGC triplets is less clear. In this study we analysed CAG and GGC repeat lengths in men with a history of cryptorchidism, associated or not with impairment of sperm production, in comparison with normal fertile subjects.
  
  
  METHODS
  We analysed CAG and GGC repeat lengths in a group of 105 ex-cryptorchid men in comparison with 115 fertile non-cryptorchid men.
  
  
  RESULTS
  No difference was found between patients and controls in the mean and median values, and in distribution of CAG and GGC, when considered separately. However, the analysis of the joint distribution of CAG and GGC showed that some combinations are significantly more frequent in men with bilateral cryptorchidism (who frequently presented severe testiculopathies), in a manner similar to that found in idiopathic infertile subjects.
  
  
  CONCLUSIONS
  Although further studies are needed to elucidate the possible role of specific CAG/GGC combinations as a causative factor, these data suggest a possible association between androgen receptor gene polymorphisms and cryptorchidism.
authors.affiliation: University of Padova, Department of Histology, Microbiology, and Medical Biotechnologies, Centre for Male Gamete Cryopreservation, 35121 Padova, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Ferlin
authors.forename: Andrea
authors.initials: A
authors.lastname: Garolla
authors.forename: Andrea
authors.initials: A
authors.lastname: Bettella
authors.forename: Lucia
authors.initials: L
authors.lastname: Bartoloni
authors.forename: Cinzia
authors.initials: C
authors.lastname: Vinanzi
authors.forename: Alberto
authors.initials: A
authors.lastname: Roverato
authors.forename: Carlo
authors.initials: C
authors.lastname: Foresta
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003456:Cryptorchidism / Q000235:genetics* / Q000503:physiopathology; D005787:Gene Frequency; D006801:Humans; D008297:Male; D008499:Medical Records; D011110:Polymorphism, Genetic; D011446:Prospective Studies; D011944:Receptors, Androgen / Q000235:genetics*; D013091:Spermatogenesis; D018911:Trinucleotide Repeats
chemical_list: D011944:Receptors, Androgen