What is aneuploidy?

Aneuploidy refers to the condition in which an organism has an abnormal number of chromosomes, specifically deviating from the typical diploid set. This typically manifests as the presence of one extra chromosome or the absence of one chromosome from a normal set, leading to a total that is not an exact multiple of the haploid number. For example, in humans, a common form of aneuploidy is Down syndrome (Trisomy 21), where there is an extra copy of chromosome 21.

This understanding of aneuploidy is essential in genetics and cell biology, as it can lead to various developmental and health issues. The normal chromosomal set, known as euploidy, contrasts with aneuploidy, highlighting the significance of having the correct number of chromosomes for proper cellular function and organismal development.