title: Risk of trisomy 21 in offspring of patients with Klinefelter's syndrome.
abstract: Intracytoplasmic sperm injection (ICSI) has given some patients with Klinefelter's syndrome (ie, men with an XXY sex-chromosome profile) the chance to become fathers, but the genetic makeup of the spermatozoa used for the injection is a concern. We studied the segregation of the sex chromosomes and chromosomes 1 and 21 by multicolour fluorescence in-situ hybridisation in a patient with non-mosaic Klinefelter's syndrome who was a candidate for ICSI. As other workers have found, we saw a higher rate of 24,XX and 24,XY spermatozoa in the patient than in controls. However, we also found a much higher frequency of disomy 21 in the spermatozoa of this patient than in controls (6.2 vs 0.4%). Any child conceived by ICSI using this man's sperm will thus have a proportionally higher risk of trisomy 21.
authors.forename: S
authors.initials: S
authors.lastname: Hennebicq
authors.forename: R
authors.initials: R
authors.lastname: Pelletier
authors.forename: U
authors.initials: U
authors.lastname: Bergues
authors.forename: S
authors.initials: S
authors.lastname: Rousseaux
mesh_terms: D002869:Chromosome Aberrations; D004314:Down Syndrome / Q000175:diagnosis / Q000209:etiology; D005820:Genetic Testing; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007713:Klinefelter Syndrome / Q000235:genetics*; D008297:Male; D020554:Sperm Injections, Intracytoplasmic; D013094:Spermatozoa / Q000166:cytology*