clastogen (n.), clastogenic (adj.)

https://doi.org/10.1351/goldbook.10527
Agent causing chromosome breakage and (or) the consequent gain, loss, or rearrangement of pieces of chromosomes.
Source:
PAC, 2016, 88, 713. (Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)) on page 736 [Terms] [Paper]