An abnormal number of chromosomes, usually associated with miscarriage, or developmental abnormalities such as Down’s syndrome where there are three copies of chromosome 21 instead of two.
Condition in which the number of chromosomes is either more or fewer than normal.
The state in which there is an abnormal number of chromosomes: for example, down’s syndrome and turner’s syndrome.
Condition of having an abnormal number of chromosomes for the species indicated.