title: Clinical diagnostic testing for the cytogenetic and molecular causes of male infertility: the Mayo Clinic experience.
abstract: OBJECTIVE
  Approximately 8% of couples attempting to conceive are infertile and male infertility accounts for approximately 50% of infertility among couples. Up to 25% of males with non-obstructive infertility have chromosomal abnormalities and/or microdeletions of the long arm of the Y-chromosome. These are detected by conventional chromosome and Y-microdeletion analysis. In this study, we reviewed the results of testing performed in the Mayo Clinic Cytogenetics and Molecular Genetics Laboratories and compared our findings with previously published reports.
  
  
  METHODS
  This study includes 2,242 chromosome studies from males ≥18 years of age referred for infertility between 1989 and 2000 and 2,749 Y-deletion molecular studies performed between 2002 and 2009.
  
  
  RESULTS
  14.3% of infertile males tested by karyotyping had abnormalities identified. These include: (258) 47,XXY and variants consistent with Klinefelter syndrome, (3) combined 47,XXY and balanced autosomal rearrangements, (9) 47,XYY, (9) Y-deletions, (7) 46,XX males, (32) balanced rearrangements, and (1) unbalanced rearrangement. 3.6% of males tested for Y-microdeletion analysis had abnormalities identified, 90% of which included a deletion of the AZFc region.
  
  
  CONCLUSIONS
  This study highlights the need of males suffering from non-obstructive infertility to have laboratory genetic testing performed. An abnormal finding can have significant consequences to assisted reproductive techniques and fertility treatment, and provide a firm diagnosis to couples with longstanding infertility.
authors.affiliation: Clinical Biochemical Genetics, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN 55902, USA. Hofherr.Sean@Mayo.edu
authors.forename: Sean E
authors.initials: SE
authors.lastname: Hofherr
authors.forename: Anne E
authors.initials: AE
authors.lastname: Wiktor
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Kipp
authors.forename: D Brian
authors.initials: DB
authors.lastname: Dawson
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Van Dyke
mesh_terms: D059786:Abnormal Karyotype; D000293:Adolescent; D000328:Adult; D053713:Azoospermia / Q000235:genetics; D002872:Chromosome Deletion; D041322:Chromosomes, Human, Y / Q000235:genetics*; D020732:Cytogenetic Analysis / Q000379:methods; D006801:Humans; D007248:Infertility, Male / Q000175:diagnosis* / Q000235:genetics*; D007713:Klinefelter Syndrome / Q000175:diagnosis; D008297:Male; D009845:Oligospermia / Q000175:diagnosis; D012189:Retrospective Studies; D013094:Spermatozoa / Q000166:cytology*