Maye gurbin kwayoyin halitta shine canji na dindindin a cikin jerin DNA wanda ya zama kwayar halitta. Yana iya haɗawa da canje-canje zuwa nucleotide guda ɗaya ko manyan sassan kwayoyin halitta ko kwayoyin halitta. Maye gurbi na iya faruwa nan take ko kuma a jawo shi ta hanyar fallasa wasu sinadarai, radiation, ko wasu abubuwan muhalli. Wadannan maye gurbi na iya shafar aikin furotin da kwayoyin halitta suka tsara don su, wanda ke haifar da cututtuka iri-iri ko cututtuka.