Cells that are genetically identical.
Use in clinical context
When cells divide by mitosis two genetically identical, therefore clonal, daughter cells are produced. Cells in a person’s body are usually clonal (as they arose from a single cell) and populations of bacteria and viruses are also often clonal. When genomic variants arise within a cell lineage or populations of bacteria or viruses, these are no longer clonal, as they are now genetically different. However, if these cells with the variants then divide a new clonal population will be created. Cancer cells can be classed as clonal. Identification of variants within a population of cancer cells can inform the diagnosis, prognosis or treatment of the disease.