Aneugen

An aneugen is a substance that causes a daughter cell to have an abnormal number of chromosomes or aneuploidy. A substance's aneugenicity reflects its ability to induce aneuploidy.

Exposure of males to lifestyle, environmental and/or occupational hazards may increase the risk of spermatozoa aneuploidy. Tobacco smoke contains chemicals that cause DNA damage. (See Tobacco smoking#Health.) Smoking also can induce aneuploidy. For instance, smoking increases chromosome 13 disomy in spermatozoa by 3-fold and YY disomy by 2-fold.