Intra-individual and inter-individual variations in sperm aneuploidy frequencies in normal men

Objective: To investigate whether there are intra-individual and/or inter-individual variations in sperm aneuploidy frequencies within the normal male population, and, if this is the case, whether they are sporadic or time-stable variants. Design: Prospective study. Setting: University research laboratory. Patient(s): Ten men aged 18-32 years. Intervention(s): None. Main Outcome Measure(s): Fluorescence in situ hybridization was used to investigate sperm aneuploidy frequencies for chromosomes X, Y, 13, and 21 in serial semen samples collected over a period of 12-18 months. Result(s): Intra-individual and inter-individual variations were investigated by comparing serial samples from the same donor and by comparing the donors with each other, respectively. Intra-individual variations were found in all 10 donors for at least one investigated chromosome; variations tended to be sporadic events affecting only one time point. Inter-individual variations were found for all chromosomes (except XX and YY disomy and disomy 21), with three men identified as stable variants, consistently producing higher levels of aneuploidy for at least one of the following aneuploidies: sex chromosome nullisomy; disomy 13, or diploidy. Conclusion(s): These results suggest that there are a number of factors and mechanisms that have the potential to sporadically or consistently affect sperm aneuploidy.