Frequency of human sperm carrying structural aberrations of chromosome 1 increases with advancing age

Objective: To investigate the association between male age and the frequency of sperm with de novo structural chromosomal abnormalities. Design: Semen specimens collected from two groups of 10 healthy, nonsmoking men, aged 22-28 and 65-80 years, were analyzed with the use of a multicolor fluorescence in situ hybridization assay for detecting breaks, segmental duplications and deletions, and aneuploidy and diploidy involving chromosome 1. Setting: Healthy volunteer workers and retirees from a government research environment. Main Outcome Measure: Sperm carrying numerical and structural chromosomal abnormalities. Result(s): We detected significant increases in the frequency of sperm carrying breaks and segmental duplications and deletions of chromosome I among older men compared with younger men. Older men carried twice the frequency of sperm with segmental duplications and deletions of chromosome 1. The frequency of sperm carrying breaks within the 1q12 fragile-site region nearly doubled in older men. In contrast to female gametes, there was no effect of age on the frequency of sperm with numerical chromosomal abnormalities. Conclusion: Our findings suggest that advancing male age is associated with a gradual and significant increase in the risk of fathering children with various chromosomal defects such as segmental aneusomy syndromes.