This study explores the relationship between sperm structural aberrations and age by using a multicolor multichromosome FISH strategy that provides information on the incidence of duplications and deletions on all the autosomes. ToTelvysion kit (Abbott Molecular, Abbott Park, IL, USA) with telomere-specific probes was used. We investigated the sperm of 10 male donors aged from 23 to 74 years old. The donors were divided into two groups according to age, a cohort of five individuals younger than 40 and a cohort of five individuals older than 60 years. The goal of this study was to determine (1) the relationship between donor age and frequency and type of chromosome structural abnormalities and (2) chromosomes more frequently involved in sperm structural aberrations. We found that the older patients had a higher rate of structural abnormalities (6.6%) compared with the younger cohort (4.9%). Although both duplications and deletions were seen more frequently in older men, our findings demonstrate the presence of an excess of duplications versus deletions in both groups at a ratio of 2 to 1. We demonstrate that the distribution of duplications and deletions was not linear along the chromosomes, although a trend toward a higher rate of abnormalities in larger chromosomes was observed. This work is the first study addressing the frequencies of sperm chromosome structural aberrations of all autosomes in a single assay thus making a contribution to the clarification of the amount and origin of damage present in human spermatozoa and in relation to age.

This study explores the relationship between numerical chromosome abnormalities in sperm and age in healthy men. We performed FISH in the spermatozoa of 10 donors from the general population: 5 men younger than 40 years of age and 5 fertile men older than 60 years of age. For each chromosome, 1,000 sperm nuclei were analyzed, with a total of 15,000 sperm nuclei for each donor. We used a single sperm sample per donor, thus minimizing intra-donor variability and optimizing consistent analysis. FISH with a TelVysion assay, which provides data on aneuploidy of 19 chromosomes, was used in order to gain a more genome-wide perspective of the level of aneuploidy. Aneuploidy and diploidy rates observed in the younger and older groups were compared. There were no significant differences in the incidence of autosomal disomy, sex chromosome disomy, total chromosome disomy, diploidy, nor total numerical abnormalities between younger and older men. This work confirms that aneuploidy of the sex chromosomes is more common than that of autosomes and that this does not change with age. Our results suggest that some probe combinations have a tendency to indicate higher levels of diploidy, thus potentially affecting FISH results and highlighting the limitations of FISH.