Medical Genetics Chromosomal instability in which new aberrations(though often not of the type characteristic of GO/G1 damage) continue to arise many generations after irradiation represents a form of genomic insta bility and genomic instability is prominent d uring neoplastIc progression.Medical Genetics Chromosomal instability, in which new aberrations (though often not of the type characteristic of G0/G1 damage) continue to arise many generations after irradiation, represents a form of genomic instability, and genomic instability is prominent during neoplastic progression