title: Molecular and cytogenetic investigation of Y chromosome deletions over three generations facilitated by intracytoplasmic sperm injection.
abstract: BACKGROUND
  The azoospermic factor (AZF) region is critical for normal spermatogenesis since microdeletions and partial deletions have been associated with infertility. We investigate the diagnostic ability of karyotyping in detecting clinically relevant Y chromosome deletions. The clinical significance of heterochromatin deletions, microdeletions and partial AZFc deletions is also evaluated.
  
  
  METHODS
  A patient with a Yq deletion, affected by severe oligoasthenoteratozoospermia, underwent intracytoplasmic sperm injection (ICSI) which resulted in the birth of a healthy baby boy. The patient, his father and his son underwent Y chromosome microdeletion and partial AZFc deletion screening. We also studied the aneuploidy rate in the sperm of the patient by fluorescent in situ hybridization.
  
  
  RESULTS
  AZF microdeletions were absent in the family. However, microdeletion analysis confirmed that the Yq deletion was limited to the heterochromatin. We found a partial AZFc gr/gr deletion in all three family members. We observed an increased rate of sex chromosome aneuploidy in the infertile patient.
  
  
  CONCLUSIONS
  Cytogenetic analysis was misleading in identifying the Yq breakpoint. Infertility observed in the patient was associated with the gr/gr partial deletion. However, because of the incomplete penetrance of gr/gr deletions, the consequence of the vertical transmission of the deletion through ICSI remains unknown.
authors.affiliation: Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Agata
authors.initials: A
authors.lastname: Minor
authors.forename: Edgar Chan
authors.initials: EC
authors.lastname: Wong
authors.forename: Karynn
authors.initials: K
authors.lastname: Harmer
authors.forename: Sai
authors.initials: S
authors.lastname: Ma
mesh_terms: D000328:Adult; D000782:Aneuploidy; D053627:Asthenozoospermia / Q000235:genetics / Q000628:therapy; D002872:Chromosome Deletion; D041322:Chromosomes, Human, Y / Q000235:genetics*; D020732:Cytogenetic Analysis; D005191:Family Characteristics; D006570:Heterochromatin / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007231:Infant, Newborn; D007248:Infertility, Male / Q000235:genetics* / Q000628:therapy; D008297:Male; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods*
chemical_list: D006570:Heterochromatin