Relationship between clinical phenotype, semen parameters and aneuploidy frequency in sperm nuclei of 50 infertile males

Abstract

The purpose of this study was to analyse the frequency of disomy for chromosomes 1, 13, 14, 18, 21, 22, X and Y in sperm nuclei of 50 infertile men and 10 healthy probands of proven fertility. Semen parameters (sperm count, global motility and morphology), urological clinical examination, genital ultrasound and lymphocyte karyotyping were performed for each patient. Disomy frequency was established by fluorescence in situ hybridization by using whole chromosome paint probes. The mean rate of disomy for the various autosomes studied was higher in infertile males than in subjects of proven fertility. Interchromosomal and interindividual differences in the disomy frequency were observed between the 50 patients. The mean frequency of homodisomy YY and heterodisomy XY was increased in spermatozoa of patients with low semen quality parameters (0.24% and 0.54%, respectively). The disomy frequency in infertile males was directly correlated with the severity of oligospermia. However, no relationship was established between aneuploidy rate, sperm motility, morphology or clinical phenotype. These results support the hypothesis that, during spermatogenesis of males with sperm parameter alterations, a decreased frequency of meiotic chromosome pairing and crossing over may lead to spermatogenesis arrest at the meiosis stage and/or to an increase of meiotic nondisjunctions. Meiotic arrest in some germ cells may be responsible for oligospermia and nondisjunctions in other cells for aneuploidy in mature male gametes.

Detection of aneuploidy rate for chromosomes X, Y and 8 by fluorescence in-situ hybridization in spermatozoa from patients with severe non-obstructive oligozoospermia

“…Our data are in discordance with the data found by Morel et al [20] and Rives et al [21]. Indeed, Morel et al [20] have conducted a study on human semen samples randomly selected from a population of men undergoing an infertility work up and did not established a correlation between subject age and disomy frequencies.…”

“…As shown in our study, inverse relationships between sperm concentration and the mean frequency of disomy of sex chromosome and diploidy were found. Our results are in accordance with the data of many other studies that reported significant negative correlations between sperm concentration and the mean frequency of disomy, especially for the sex chromosomes [6,10,15,21,22]. However, other studies did not show a significant correlation between sex disomy rates and sperm concentration [3,20,23,24].…”

“…Indeed, Morel et al [20] have conducted a study on human semen samples randomly selected from a population of men undergoing an infertility work up and did not established a correlation between subject age and disomy frequencies. Rives et al [21] also confirmed that the disomy frequency is not correlated to subject age.…”

“…Studies carried out to investigate the correlation between chromosome aneuploidy and morphologically abnormal spermatozoa by FISH have produced no consistent data. Some studies did not found a statistically correlations between the frequency of disomy for all the chromosomes analysed and the sperm morphology [6,21]. However other studies show a statistically significant correlation between aneuploidy and poor spermatozoa morphology [9,22].…”

Chromosomal segregation in spermatozoa of five Robertsonian translocation carriers t(13;14)

“…Most carriers of Robertsonian translocations have oligozoospermia. This may be a result others either did not show it [7,24,25] or attributed the increased aneuploidy rate due to the oligoasthenoteratozoospermia (OAT) phenotype frequency observed within these patients [10,26,27] or only to the ICE. For this reason, other FISH studies on spermatozoa from a large number of Robertsonian, translocations carriers should be performed in order to give precise information about the genetic risks linked to those who carry structural chromosomes abnormalities.…”