Meiotic studies in two human reciprocal translocations and their association with spermatogenic failure.
BACKGROUND
Reciprocal translocations are often associated with infertility in male carriers. However, some carriers present normal semen profiles and are identified because of repetitive pregnancy failures.


METHODS
Here, we report two different cases of reciprocal translocations. The first patient carried a t(10;14) and was normozoospermic. The second patient carried a t(13;20) and was azoospermic. Synaptonemal complexes from both carriers were analysed using immunocytogenetic techniques and multi-centromere fluorescent in situ hybridization (cenM-FISH).


RESULTS
Associations between the quadrivalent and the sex body or other autosomes were seen only in the t(13;20) carrier. Heterosynapsis was observed only in the t(10;14) carrier. Synaptic pairing abnormalities were seen in 71% of the spreads in the t(13;20) carrier and 30% of the spreads in the t(10;14) carrier. Recombination frequency was decreased in the t(13;20) carrier, but not in the t(10;14) carrier.


CONCLUSIONS
By comparing these two different translocation carriers with different fertility outcomes, we discuss the possible mechanisms by which translocations might cause the spermatogenesis process to fail.
Oliver-Bonet
M
M
University of Calgary, Department of Obstetrics and Gynecology, Faculty of Medicine, University of Calgary, Calgary T2N 4N1, Canada.
Benet
J
J
Sun
F
F
Navarro
J
J
Abad
C
C
Liehr
T
T
Starke
H
H
Greene
C
C
Ko
E
E
Martin
R H
RH
D000328:Adult; D002879:Chromosomes, Human, Pair 10; D002882:Chromosomes, Human, Pair 13; D002883:Chromosomes, Human, Pair 14; D002890:Chromosomes, Human, Pair 20; D005298:Fertility; D006579:Heterozygote; D006801:Humans; D007248:Infertility, Male / Q000235:genetics / Q000503:physiopathology*; D008297:Male; D008540:Meiosis; D009845:Oligospermia / Q000235:genetics / Q000503:physiopathology; D013091:Spermatogenesis / Q000235:genetics*; D014178:Translocation, Genetic