Also found in: Dictionary, Thesaurus, Wikipedia.
Related to chromosomal mutation: gene mutation
chromosomal mutationchanges to the chromosome complement or structure of cells or organisms. There are two major types:
- numerical, affecting whole chromosomes (see POLYPLOID and ANEUPLOIDY), and
- structural, affecting genetic arrangement within chromosomes. These are usually of a fairly major type (compare POINT MUTATION) and often cause severely adverse effects. Such structural mutations are classified into various types:
- inversion, the rearrangement of a chromosomal segment so that it has the reverse sequence, e.g. ABCDE ----> ADCBE;
- deletions, the removal of a segment;
- duplication, the repeating of a segment either next door to the original or elsewhere along the chromosome;
- translocation, the exchange of segments between nonhomologous chromosomes.