18, X, Y aneuploidies and transmission electron microscopy studies in spermatozoa from five carriers of different reciprocal translocations

Abstract

We analysed ejaculated spermatozoa from five infertile men with different balanced reciprocal translocations to contribute to the study of meiotic segregation of chromosomes 18, X and Y and also to evaluate sperm morphology by transmission electron microscopy (TEM) analysis. Conventional lymphocyte karyotype analyses highlighted dif ferent reciprocal balanced translocations: t(12;13), t(4;9), t(X;8), t(8;10) and t(3;16). Semen analysis was performed by light and TEM. Fluorescence in situ hybridization was performed directly on sperm nuclei using centromeric probes for chromosomes 18, X and Y. The carriers of the balanced reciprocal translocations considered in the pres ent study showed a very similar pattern of sperm pathologies: diffused presence of apoptosis and immaturity. All patients showed meiotic segregation derangements, highlighted by the presence of sperm diploidies and sex chro mosome disomies particularly related to the failure of the first meiotic division. However, an increased incidence of chromosome 18 aneuploidy was detected in spermatozoa from t(X;8) and t(8;10) carriers. We have also reported values from sex chromosomes such as t(X;8), although the X chromosome was involved in translocation. Since pa tients with reciprocal translocations and spermatogenetic impairment are candidates for intracytoplasmic sperm in jection cycles, the study of sperm parameters, and particularly of the level of aneuploidy rates, would provide better information for couples at risk and would contribute to the data in the literature for a better understanding of the ef fects of chromosomal rearrangement on the whole meiotic process and, in particular, on chromosomes not involved in translocation.

High-magnification sperm selection does not decrease the aneuploidy rate in patients who are heterozygous for reciprocal translocations

“…All the balanced translocation rates were in accordance with literature values (i.e. a mean aneuploidy rate close to 50 % for translocation segregation and around 2 % for the ICE [13,23,28]). Due to the small sample size for ICSI and IMSI selected spermatozoa, no statistical analyses were performed.…”

The association between environmental exposure to pyrethroids and sperm aneuploidy

“…Sex chromosome disomy frequencies estimated for the present study were higher than previously reported ranges among men using manual counting (XX, 0.03-0.37; YY, 0.04-0.21; XY, 0.06-0.42, sex chromosome disomy 0.27) (Egozcue et al, 1997;Templado et al, 2005Templado et al, , 2011. In a study of fertility clinic patients who were known reciprocal translocation carriers, XY disomy was as high as 4.1% (Moretti et al, 2009). Additionally, in a recent studies of sperm disomy among andrology clinic patients using automated methods, Tempest et al (2010) and McAuliffe et al (2012) also reported higher total sex-chromosome disomy (averaging between 1.3% and 1.90% total disomy) compared with previously reported ranges (Egozcue et al, 1997).…”

Environmental Exposure to Polychlorinated Biphenyls and p,p ´-DDE and Sperm Sex-Chromosome Disomy

“…In a study of fertility clinic patients who were known reciprocal translocation carriers, XY disomy was as high as 4.1% (Moretti et al 2009). Because we did not routinely perform karyotypes, we do not know the prevalence of underlying reproductive conditions such as Robertsonian translocations in our clinic sample.…”