polyploid

Definition: Having three or more sets of homologous chromosomes.

According to the number of sets, one can distinguish tetraploidy, hexaploidy, oktoploidy and dekaploidy.

While polyploidy, a state of having fully duplicated sets of chromosomes per cell, has been described in normally developing bone marrow megakaryocytes or as an adaptive response in other cell types, aneuploidy is never detected in normal cells.

Tetraploidy or aneuploidy can be induced by several signals and it is highly prevalent in different forms of cancers, suggesting a role for this cell cycle state in promoting cellular transformation.

See also

 haploid
 diploid
 aneuploid
 euploid
  ploidy anomalies

References

 Nguyen HG, Ravid K. Tetraploidy/aneuploidy and stem cells in cancer promotion: The role of chromosome passenger proteins. J Cell Physiol. 2006 Jul;208(1):12-22. PMID: 16331679

 Comai L. The advantages and disadvantages of being polyploid. Nat Rev Genet. 2005 Nov;6(11):836-46. PMID: 16304599