aneuploidy
Sign in to saveAneuploidy is the presence of an abnormal number of chromosomes in a cell, for example a human somatic 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.
Key facts
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- Down Syndrome Karyotype.png
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- Chromosomes in Down syndrome, one of the most common human conditions due to aneuploidy. There are three chromosomes 21 (in the last row).
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- Medical genetics
via Wikipedia infobox
Article
12 sectionsContents
- Chromosomes
- Mechanisms
- Somatic mosaicism in the nervous system
- Somatic mosaicism in cancer
- Partial aneuploidy
- Aneugens
- Diagnosis
- Types
- Terminology
- See also
- References
- External links
Aneuploidy is the presence of an abnormal number of chromosomes in a cell, for example a human somatic 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 aneuploid. Aneuploidy originates during cell division when the chromosomes do not separate properly between the two cells (nondisjunction). Most cases of aneuploidy 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 aneuploidy is more dangerous than sex chromosome aneuploidy, as autosomal aneuploidy is almost always lethal to embryos that cease developing because of it.