<unk>  is a change in the number of chromosomes that can lead to a chromosomal disorder.  The most recognized forms of<unk>  are the trisomy diseases of Down syndrome and Edwards syndrome. Trisomy may not necessarily be present in all cells in an individual.  It may be detected in just a specific tissue or within different cells in a tissue.  When the presence of chromosomal abnormalities occurs differentially within an individual, it is called chromosomal mosaicism.  In general, as we would expect, individuals who are mosaic for a chromosome change tend to have a less severe form of the syndrome present than full trisomy individuals.  Critical examples of mosaicism are found in leukemia cases, specifically; chronic lymphocytic leukemia (CLL) which is a trisomy of chromosome 12 and acute myeloid leukemia (AML) prognosis which is a trisomy of chromosome 8.<unk>  is common in cancerous cells.
Aneuploidy
Polyploidy
Anembryonic gestation
Monosomy
Unwanted pregnancy
Maternal deprivation
Non-mendelian inheritance
Hypoplasia