title: FISH analysis of Y chromosome long arm deletions in subfertile men considering ICSI. A report of two cases.
abstract: BACKGROUND
  Men with Y chromosome long arm deletions, resulting in infertility, form a very significant group of patients, with a view to treatment. With recent advances in assisted reproductive techniques, it is expected that if these patients undergo intracytoplasmic sperm injection, their male offspring will inherit the same deleted regions of Y chromosomes. Hence, characterization of these deleted Y regions provides information, allowing patients to make informed decisions about reproduction. Fluorescence in situ hybridization (FISH), with probes along the Y chromosome, is very helpful in identification of the exact breakpoints.
  
  
  METHODS
  Two men with complaints of infertility on examination showed low or no sperm in their semen samples. Routine cytogenetic analysis of the peripheral blood showed a small marker chromosome. This marker was identified as the Y chromosome by FISH. Subsequently, other probes along the Y long arm were used to characterize the extent of the deletion.
  
  
  CONCLUSIONS
  With the use of fluorescence-labelled probes, it was possible to identify the extent of the Y chromosome deletion. The distal Yq11 region had been lost in both patients, resulting in oligospermia and azoospermia. Characterizing markers by FISH gave good guidelines to the patients about the possible effects on offspring, allowing them to make appropriate decisions.
authors.affiliation: Department of Obstetrics and Gynaecology, Nationl University Hospital, 5 Lower Kent Ridge Road, Singapore 119074.
authors.forename: Leena A
authors.initials: LA
authors.lastname: Gole
authors.forename: Soon Chye
authors.initials: SC
authors.lastname: Ng
mesh_terms: D000328:Adult; D002872:Chromosome Deletion; D020732:Cytogenetic Analysis; D005819:Genetic Markers / Q000235:genetics; D005820:Genetic Testing; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007621:Karyotyping; D008297:Male; D009845:Oligospermia / Q000175:diagnosis* / Q000235:genetics* / Q000628:therapy; D013076:Sperm Count; D020554:Sperm Injections, Intracytoplasmic; D014998:Y Chromosome / Q000235:genetics*
chemical_list: D005819:Genetic Markers