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Genetic and Rare Diseases Information Center (GARD)

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Trisomy 13


Other Names for this Disease

  • Chromosome 13, trisomy 13 complete
  • Complete trisomy 13 syndrome
  • D trisomy syndrome (formerly)
  • Patau syndrome
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.

Overview

What is trisomy 13?

What are the signs and symptoms of trisomy 13?

What causes trisomy 13?

How might trisomy 13 be treated?

What is trisomy 13?

Trisomy 13, also called Patau syndrome, is a genetic disorder in which all or a portion of chromosome 13 appears three times (trisomy) rather than twice in cells of the body. In some affected individuals, only a percentage of cells may contain the extra 13th chromosome (mosaicism), whereas other cells contain the normal chromosomal pair.[1][2][3] The extra material interferes with normal development, leading to severe intellectual disability and physical abnormalities in many parts of the body. Most cases of trisomy 13 are not inherited and result from random events during the formation of eggs and sperm in healthy parents.[2][3] Due to the presence of several life-threatening medical problems, many infants with trisomy 13 die within their first days or weeks of life. Only about 5-10 percent of children with this condition live past their first year.[2]
Last updated: 1/9/2012

What are the signs and symptoms of trisomy 13?

Trisomy 13 is a chromosomal condition associated with severe intellectual disability and physical abnormalities in many parts of the body. Individuals with this condition often have heart defects, brain or spinal cord abnormalities, very small or poorly developed eyes (microphthalmia), extra fingers and/or toes (polydactyly), cleft lip or palate, and decreased muscle tone (hypotonia).[2] Many infants with trisomy 13 fail to grow and gain weight at the expected rate (failure to thrive), have severe feeding difficulties, and episodes in which there is temporary cessation of spontaneous breathing (apnea).[1]

 
Other features or trisomy 13 may include:[3]

 

Last updated: 1/9/2012

What causes trisomy 13?

Almost all cases of trisomy 13 are caused by random events during the formation of an egg or sperm in healthy parents.  Most often, the error occurs during cell division when a pair of chromosomes 13 stick together in one cell instead of separating into two cells (this is called nondisjunction); this produces an egg or sperm cell (reproductive cells) with an extra copy of chromosome 13.  If one of these reproductive cells with an extra copy of chromosome 13 contributes to the genetic makeup of a child, the child will have an extra chromosome 13 in each cell of the body and have trisomy 13.

Translocation trisomy 13 occurs when a child inherits an extra chromosome 13 that is attached to another chromosome.  A parent with normal chromosomes can have a rearrangement of genetic material between chromosome 13 and another chromosome such that the two chromosome become attached to each other. These rearrangements are called balanced translocations because there is no extra material from chromosome 13. A person with a balanced translocation involving chromosome 13 has an increased chance of having a child with trisomy 13, because they may pass on the chromosome that is abnormally attached to chromosome 13, resulting in the child having extra chromosome material.[4]
Last updated: 4/16/2012

How might trisomy 13 be treated?

Treatment of children with trisomy 13 is planned on a case-by-case basis. The type of treatment given depends on the patient's individual condition.[3] Surgical interventions are generally withheld for the first few months of life because of the high mortality rates of babies with trisomy 13. Parents and medical personnel must carefully weigh decisions about extraordinary life-prolonging measures against the severity of the neurological and physical defects that are present and the likelihood of postsurgical recovery or prolonged survival.[5]
Last updated: 1/9/2012

References
  1. Trisomy 13 Syndrome. National Organization for Rare Disorders (NORD). 2007; http://www.rarediseases.org/search/rdbdetail_abstract.html?disname=Trisomy%2013%20Syndrome. Accessed 10/13/2009.
  2. Trisomy 13. Genetics Home Reference (GHR). 2009; http://ghr.nlm.nih.gov/condition=trisomy13. Accessed 10/13/2009.
  3. Chambers D. Trisomy 13. MedlinePlus. 2009; http://www.nlm.nih.gov/medlineplus/ency/article/001660.htm. Accessed 10/13/2009.
  4. Trisomy 13. Genetics Home Reference. January 2009; http://ghr.nlm.nih.gov/condition/trisomy-13. Accessed 1/9/2012.
  5. Best RG, Stallworth J. Patau Syndrome. eMedicine. 2007; http://emedicine.medscape.com/article/947706-overview. Accessed 10/13/2009.


Other Names for this Disease
  • Chromosome 13, trisomy 13 complete
  • Complete trisomy 13 syndrome
  • D trisomy syndrome (formerly)
  • Patau syndrome
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.