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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.

Your Question

Are there treatments for trisomy 13? What is the prognosis? What is life like for those who have this condition?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

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 (a trisomy) rather than twice in cells of the body. In some affected people, only a portion of cells may contain the extra chromosome 13 (called mosaic trisomy 13), whereas other cells contain the normal chromosomal pair.[1][2][3] Trisomy 13 causes severe intellectual disability and many physical abnormalities, such as heart defects; brain or spinal cord abnormalities; very small or poorly developed eyes (microphthalmia); extra fingers or toes; cleft lip with or without cleft palate; and weak muscle tone (hypotonia). Most cases are not inherited and result from random errors during the formation of eggs or sperm in healthy parents.[2] Due to various life-threatening medical problems, many infants with trisomy 13 do not survive past the first days or weeks of life.[2]
Last updated: 1/20/2015

What are the signs and symptoms of trisomy 13?

Trisomy 13 is 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: 1/20/2015

What are the genetic changes related to trisomy 13?

Most cases of trisomy 13 result from having three copies of chromosome 13 in each cell in the body instead of the usual two copies. The extra genetic material disrupts the normal course of development, causing the characteristic features of trisomy 13.[2]

Trisomy 13 can also occur when part of chromosome 13 becomes attached (translocated) to another chromosome during the formation of reproductive cells (eggs and sperm) or very early in fetal development. Affected people have two normal copies of chromosome 13, plus an extra copy of chromosome 13 attached to another chromosome. In rare cases, only part of chromosome 13 is present in three copies. The physical signs and symptoms in these cases may be different than those found in full trisomy 13.[2]

A small percentage of people with trisomy 13 have an extra copy of chromosome 13 in only some of the body's cells. In these people, the condition is called mosaic trisomy 13. The severity of mosaic trisomy 13 depends on the type and number of cells that have the extra chromosome. The physical features of mosaic trisomy 13 are often milder than those of full trisomy 13.[2]

Last updated: 1/20/2015

How might trisomy 13 be treated?

Treatment for trisomy 13 depends on the affected individual's condition and is generally symptomatic and supportive.[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 post-surgical recovery or prolonged survival.[4]
Last updated: 1/20/2015

What is the long-term outlook for people with trisomy 13?

Trisomy 13 involves multiple abnormalities, many of which are life-threatening. More than 80% of children with this condition do not survive past the first month of life. For those that do survive, complications are common and may include:[3]
  • Breathing difficulty or lack of breathing (apnea)
  • Deafness
  • Feeding problems
  • Heart failure
  • Seizures
  • Vision problems

People with trisomy 13 who survive infancy have severe intellectual disability and developmental delays, and are at increased risk for cancers.[4]

Last updated: 1/20/2015

Where can I learn more about living with trisomy 13?

Information and supportive resources for trisomy 13 can be obtained from the Support Organization for Trisomy 18, 13, and Related Disorders (SOFT) and Living With Trisomy 13. These groups provide psychosocial support to families dealing with this condition on a day-to-day basis.   
Last updated: 10/13/2009

References
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.