title: Mosaic ring Y chromosome in two normal healthy men with azoospermia.
abstract: OBJECTIVE
  To better define by molecular and cytogenetic techniques ring Y chromosomes detected in 2 infertile men.
  
  
  METHODS
  Case report.
  
  
  METHODS
  Molecular genetics/cytogenetics unit in a university hospital.
  
  
  METHODS
  Two infertile men with azoospermia, presenting a normal male phenotype with complete masculinization.
  
  
  METHODS
  Karyotype and genetic counseling.
  
  
  METHODS
  Metaphases were studied by standard G- and Q-banding; fluorescent in situ hybridization and PCR were performed to analyze specific Y chromosome regions.
  
  
  RESULTS
  Chromosomal analysis detected a mosaicism with a Y chromosome ring cell line in 92% (patient 1) and 95% (patient 2) of the metaphases, coexisting with a 45,X cell line in the remaining metaphases. In patient 1, PCR analysis showed the presence of AZFa region and a partial deletion of AZFb region; AZFc region was deleted. In patient 2 all three AZF regions were deleted.
  
  
  CONCLUSIONS
  A 45,X/46,X,r(Y) mosaicism can be detected not only in patients with Ullrich-Turner syndrome and in patients with various degrees of genital ambiguity but also in men presenting a normal phenotype. Their azoospermia can be explained by partial or total deletion of AZF regions.
authors.affiliation: Laboratory of Cytogenetics and Molecular Genetics, Azienda Ospedaliera Universitaria Pisana, Pisa, Italy.
authors.forename: Veronica
authors.initials: V
authors.lastname: Bertini
authors.forename: Domenico
authors.initials: D
authors.lastname: Canale
authors.forename: Maria Patrizia
authors.initials: MP
authors.lastname: Bicocchi
authors.forename: Paolo
authors.initials: P
authors.lastname: Simi
authors.forename: Angelo
authors.initials: A
authors.lastname: Valetto
mesh_terms: D000328:Adult; D041322:Chromosomes, Human, Y; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D009030:Mosaicism; D009845:Oligospermia / Q000235:genetics*; D012303:Ring Chromosomes; D012729:Sex Chromosome Aberrations