PPT Slide First Previous Next Last Index Text Slide 33 of 33 Alterations of chromosome structure can cause birth defects and cancer. Deletions, duplications, and inversions occur within one chromosome. Inversions are less likely to produce harmful effects than deletions or duplications because all the chromosome s genes are still present. Duplications, if they result in the duplication of an oncogene in somatic cells, may increase the incidence of cancer.
Translocation involves the transfer of a chromosome fragment between nonhomologous chromosomes.
Translocations may or may not be harmful. One type of translocation results in Down syndrome.