Meiotic segregation of a t(7;8)(q11.21;cen) translocation in two carrier brothers.
OBJECTIVE
To determine the meiotic segregation of a t(7;8)(q11.21;cen) translocation in two carrier brothers.


METHODS
Analysis of sperm nuclei by fluorescence in situ hybridization (FISH).


METHODS
Franche-Comté University Fertility Center in Besançon, France.


METHODS
Two oligospermic brothers with a (7;8) translocation.


METHODS
Dual FISH for chromosomes 7 and 8, and multicolor FISH for chromosomes X, Y, 15, and 18 were performed.


METHODS
Meiotic segregation differences between both brothers and controls.


RESULTS
In dual FISH 7-8, a total of 34527 (older brother) and 10023 (younger brother) spermatozoa were analyzed. The frequencies of alternate, adjacent 1, adjacent 2, and 3:1 segregations and diploidies were 56.7%, 25.1%, 11.1%, 7.06%, and 0.04%, respectively, in the older brother and 62.84%, 17.61%, 12.8%, 6.47%, and 0.28% in the younger. Also, the disomy rates of some chromosomes not implicated in the translocation would suggest a possible interchromosomal effect.


CONCLUSIONS
The similar segregation profiles for the same translocation, compared with those very divergent profiles of the other cases of studied translocations that were published in the literature, confirm that the risks of meiotic imbalances vary primarily according to the characteristics of the chromosomes involved in the rearrangement and the breakpoint position.
Morel
Frédéric
F
Laboratoire d'Histologie, Cytogénétique et Embryologie, Faculté de Médecine et des Sciences de la Sante Université Bretagne Occidentale, Brest, France. frederic.morel@chu-brest.fr
Douet-Guilbert
Nathalie
N
Roux
Christophe
C
Tripogney
Christophe
C
Le Bris
Marie-Josée
MJ
De Braekeleer
Marc
M
Bresson
Jean-Luc
JL
D000328:Adult; D016022:Case-Control Studies; D020090:Chromosome Segregation; D004171:Diploidy; D005787:Gene Frequency; D006579:Heterozygote; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008540:Meiosis / Q000235:genetics*; D013094:Spermatozoa / Q000166:cytology* / Q000502:physiology*; D014178:Translocation, Genetic