title: Chromosomal anomalies and Y-microdeletions among Chinese subfertile men in Hong Kong.
abstract: OBJECTIVE
  To report the type and frequency of chromosomal anomalies and Y-microdeletions among Hong Kong Chinese subfertile men with sperm concentrations lower than 5 million/mL. DESIGN. Retrospective study.
  
  
  METHODS
  A reproductive centre in Hong Kong.
  
  
  METHODS
  A total of 295 Chinese subfertile men who underwent both karyotyping and Y-microdeletion studies from 2000 to 2007 were categorised as having non-obstructive azoospermia (n=71), very severe oligospermia (sperm concentration>0 and <or=2 million/mL, n=158), and severe oligospermia (sperm concentration>2 and <5 million/mL, n=66).
  
  
  METHODS
  Karyotyping and Y-microdeletion studies.
  
  
  RESULTS
  The prevalence of chromosomal anomalies and Y-microdeletions in the study population were 8.5% (25/295; 95% confidence interval, 5.6-12.3%) and 6.4% (19/295; 3.9-9.9%), respectively. The total prevalence of chromosomal anomalies and Y-microdeletions was 13.2% (39/295; 95% confidence interval, 9.6-17.6%) as five cases of non-obstructive azoospermia showed both Y structural alterations and AZFbc deletion. The corresponding figures for chromosomal anomalies in the groups with non-obstructive azoospermia, very severe oligospermia, and severe oligospermia were 21.1% (15/71; 95% confidence interval, 12.3-32.4%), 5.7% (9/158; 2.6-10.5%), and 1.5% (1/66; 0.0-8.2%). While for Y-microdeletions they were 8.5% (6/71; 3.2-17.5%), 8.2% (13/158; 4.5-13.7%) and 0% (0/66; 0.0-4.4%), respectively. The respective overall prevalence rates for chromosomal anomalies and Y-microdeletions in these groups were: 22.5% (16/71; 13.5-34.0%), 13.9% (22/158; 8.9-20.3%), and 1.5% (1/66; 0.0-8.2%).
  
  
  CONCLUSIONS
  Our findings strongly support the recommendation for both karyotyping and Y-microdeletion analyses in subfertile men with sperm concentrations of 2 million/mL or lower before they undergo assisted reproduction treatment.
authors.affiliation: Department of Obstetrics and Gynaecology, The University of Hong Kong, Tsan Yuk Hospital, Hong Kong.
authors.forename: Paulina P Y
authors.initials: PP
authors.lastname: Ng
authors.forename: Mary H Y
authors.initials: MH
authors.lastname: Tang
authors.forename: Elizabeth T
authors.initials: ET
authors.lastname: Lau
authors.forename: Lucy K L
authors.initials: LK
authors.lastname: Ng
authors.forename: Ernest H Y
authors.initials: EH
authors.lastname: Ng
authors.forename: P C
authors.initials: PC
authors.lastname: Tam
authors.forename: William S B
authors.initials: WS
authors.lastname: Yeung
authors.forename: P C
authors.initials: PC
authors.lastname: Ho
mesh_terms: D000554:Ambulatory Care Facilities; D002872:Chromosome Deletion; D041322:Chromosomes, Human, Y; D016208:Databases, Factual; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D007248:Infertility, Male / Q000453:epidemiology* / Q000235:genetics*; D007621:Karyotyping; D008297:Male; D015995:Prevalence; D012189:Retrospective Studies; D012729:Sex Chromosome Aberrations / Q000706:statistics & numerical data*; D013076:Sperm Count