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Down Syndrome

What is Down syndrome?

Down syndrome is a condition in which a person has an extra chromosome or an extra piece of a chromosome. This extra copy changes how a baby's body and brain develop. It can cause both mental and physical challenges during their lifetime. Even though people with Down syndrome might act and look similar, each person has different abilities.

What causes Down syndrome?

Chromosomes are tiny "packages" in your cells that contain your genes. Genes carry information, called DNA, that controls what you look like and how your body works. People with Down syndrome have an extra copy of chromosome 21. In some cases, they may have an extra copy of part of the chromosome. Having an extra copy of a chromosome is called trisomy. So sometimes Down syndrome is also called trisomy 21.

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Results 1 - 10 of 99 for Trisomy
  1. Down Syndrome (National Library of Medicine)  
    ... an extra copy of a chromosome is called trisomy. So sometimes Down syndrome is also called trisomy 21. Down syndrome is usually not inherited. It ...
  2. Trisomy 18, also called Edwards syndrome, is a chromosomal condition associated with abnormalities in many parts of the body. Individuals with trisomy 18 often ...
  3. Trisomy 13, also called Patau syndrome, is a chromosomal condition associated with severe intellectual disability and physical ... in many parts of the body. Individuals with trisomy 13 often have heart defects, brain or spinal ...
  4. Trisomy X, also called triple X syndrome or 47,XXX, is characterized by the presence of an ... causes no unusual physical features. Most females with trisomy X have normal sexual development and are able ...
  5. Trisomy 18 is a genetic disorder in which a person has a third copy of material from ... Trisomy 18 occurs in 1 in 6000 live births. It is 3 times more common in girls ...
  6. Trisomy 13 (also called Patau syndrome) is a genetic disorder in which a person has 3 copies ... Trisomy 13 occurs when extra DNA from chromosome 13 appears in some or all of the body's ...
  7. ... due to a problem such as: Down syndrome (trisomy 21) Edwards syndrome (trisomy 18)
  8. ... 21. This form of Down syndrome is called trisomy 21. The extra chromosome causes problems with the ...
  9. Klinefelter syndrome, also called 47,XXY, is a genetic condition that occurs in males when they have an extra X chromosome. This can ...
  10. ... syndrome (KS) Klinefelter's syndrome XXY syndrome XXY trisomy Genetic Testing Registry: Klinefelter syndrome 47, XXY Klinefelter ...
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