<unk>  is the presence of an abnormal number of chromosomes in a cell, for example a human cell having 45 or 47 chromosomes instead of the usual 46. It does not include a difference of one or more complete sets of chromosomes. A cell with any number of complete chromosome sets is called a euploid cell. An extra or missing chromosome is a common cause of some genetic disorders. Some cancer cells also have abnormal numbers of chromosomes. About 68% of human solid tumors are<unk> <unk>  originates during cell division when the chromosomes do not separate properly between the two cells (nondisjunction). Most cases of<unk>  in the autosomes result in miscarriage, and the most common extra autosomal chromosomes among live births are 21, 18 and 13. Chromosome abnormalities are detected in 1 of 160 live human births. Autosomal<unk>  is more dangerous than sex chromosome<unk> , as autosomal<unk>  is almost always lethal to embryos which cease developing because of it.
Aneuploidy
Germline mosaicism
Polyploidy
Defocus aberration
Germline mutation
Robertsonian translocation
Chromosomal translocation
Heteroxeny