Sperm fluorescence in situ hybridization study of meiotic segregation and an interchromosomal effect in carriers of t(11;18).
BACKGROUND
Alanced translocations are associated with infertility, spontaneous abortions and birth defects.


METHODS
We report the analysis, by multicolour fluorescence in situ hybridization (FISH), of meiotic segregation and aneuploidy of chromosomes X, Y, 7, 8 and 21 in sperm from three men who are carriers of two different translocations involving chromosomes 11 and 18. A control group comprised ten young, healthy normospermic men.


RESULTS
The higher prevalence of alternate segregation followed by adjacent 1, adjacent 2 and 3:1, and other segregants was observed in all three patients. Two carriers of the same translocation differed only in the frequency of adjacent 2 segregation (P < 0.01). The carrier of the other translocation showed significantly higher frequency of alternate (P < 0.01) and less adjacent 1 and 3:1 segregation products (P < 0.01). An increased frequency of XY (P < 0.01), YY (P < 0.05) and diploid (P < 0.01) sperm was also detected in the group of translocation carriers compared with the control group. This difference was caused by elevated frequencies of disomy and diploidy in two of our carriers.


CONCLUSIONS
The incidence of chromosomally unbalanced or aneuploid gametes varies in the individual translocation carriers even if the same chromosomes are included in the translocation. FISH analysis provides information useful for genetic counseling and assisted reproduction.
Vozdova
Miluse
M
Department of Genetics and Reproduction, Veterinary Research Institute, Hudcova 70, 621 00 Brno, Czech Republic.
Oracova
Eva
E
Horinova
Vera
V
Rubes
Jiri
J
D000328:Adult; D000782:Aneuploidy; D020090:Chromosome Segregation; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics*; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics*; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics; D002897:Chromosomes, Human, Pair 7 / Q000235:genetics; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics; D041321:Chromosomes, Human, X / Q000235:genetics; D041322:Chromosomes, Human, Y / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008540:Meiosis / Q000502:physiology*; D013094:Spermatozoa / Q000166:cytology*; D014178:Translocation, Genetic / Q000235:genetics*