Down syndrome or Down's syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is usually associated with developmental delays, mild to moderate intellectual disability, and characteristic physical features. There are three types of Down syndrome, all with the same features: Trisomy 21, the most common type; Mosaic Down syndrome, and Translocation Down syndrome. WebWith less common types of Down syndrome, a person may have: An extra piece of chromosome 21 attached to another chromosome (translocation Down syndrome) An extra chromosome 21 in some, but not all of their cells (mosaic Down syndrome) The extra chromosome affects the way a baby's brain and body develop. The symptoms may range …
Chromosomes Fact Sheet - Genome.gov
WebJun 22, 2012 · Most cells of the human body contain 23 pairs of chromosomes—one set of chromosomes from each parent— for a total of 46 chromosomes. People with Down … WebMay 12, 2024 · Down syndrome (also known as trisomy 21) is an example of a condition caused by trisomy. People with Down syndrome typically have three copies of … duties of a caretaker in a home
Mosaic down syndrome: Definition, symptoms, and diagnosis
WebMay 12, 2024 · Down syndrome (also known as trisomy 21) is an example of a condition caused by trisomy. People with Down syndrome typically have three copies of chromosome 21 in each cell, for a total of 47 chromosomes per cell. Monosomy, or the loss of one chromosome in cells, is another kind of aneuploidy. WebFeb 16, 2024 · A person's typical number of chromosomes is 46 (in 23 pairs). A person with Down syndrome has 47 chromosomes if all other chromosome pairs are typical. Mosaic Down syndrome: This type of … WebMar 8, 2024 · Human cells normally contain 23 pairs of chromosomes. One chromosome in each pair comes from your father, the other from your mother. Down syndrome results when abnormal cell division involving … duties of a chairman