Ma'anar ƙamus na kalmar "lalacewar gado" tana nufin wani yanayi na likita ko cuta da ke yaɗuwa daga tsara zuwa wani a cikin iyali ta hanyar gadon gado. Wannan yana nufin cewa yanayin yana faruwa ne ta hanyar rashin daidaituwa ko maye gurbi a cikin daya ko fiye da kwayoyin halittar da ke yadawa daga iyaye zuwa ga ’ya’yansu. zuwa mafi muni kuma mai yuwuwar yanayin barazanar rayuwa, kamar cystic fibrosis ko cutar Huntington. Wasu sharuɗɗan gadon na iya samun tsarin gadon da ya mamaye, ma'ana mutum yana buƙatar kawai ya gaji kwafi ɗaya na kwayoyin halitta mara kyau don haɓaka yanayin, yayin da wasu kuma na iya samun tsarin rabon gado, wanda ke buƙatar kwafin nau'in nau'in gadon gado guda biyu don gado. oda domin yanayin ya bayyana.