Trisomy 13

Title

Other Names:

Patau syndrome; Chromosome 13, trisomy 13 complete; Complete trisomy 13 syndrome; Patau syndrome; Chromosome 13, trisomy 13 complete; Complete trisomy 13 syndrome; D trisomy syndrome (formerly) See More

Categories:

Chromosome Disorders; Congenital and Genetic Diseases; Digestive Diseases; Chromosome Disorders; Congenital and Genetic Diseases; Digestive Diseases; Eye diseases; Kidney and Urinary Diseases See More

Summary Summary

Trisomy 13 is a type of chromosome disorder characterized by having 3 copies of chromosome 13 in cells of the body, instead of the usual 2 copies. In some affected people, only a portion of cells contains the extra chromosome 13 (called mosaic trisomy 13), whereas other cells contain the normal chromosome pair.^[1]^[2]^[3] Trisomy 13 causes severe intellectual disability and many physical abnormalities, such as congenital 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 a random error 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: 3/17/2016

Symptoms Symptoms

Trisomy 13 is associated with severe intellectual disability and physical abnormalities in many parts of the body. People with this condition often have congenital 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]

Clenched hands (with outer fingers on top of the inner fingers)
Close-set eyes
Hernias: umbilical hernia, inguinal hernia
A hole, split, or cleft in the iris of the eye (coloboma)
Low-set ears
Scalp defects such as missing skin
Seizures
Single palmar crease
Skeletal (limb) abnormalities
Small head (microcephaly)
Small lower jaw (micrognathia)
Undescended testicle (cryptorchidism)

Last updated: 9/3/2015

The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition. Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency). Frequencies are based on a specific study and may not be representative of all studies. You can use the MedlinePlus Medical Dictionary for definitions of the terms below.

Signs and Symptoms	Approximate number of patients (when available)
Abnormality of pelvic girdle bone morphology	Very frequent (present in 80%-99% of cases)
Abnormality of the fontanelles or cranial sutures	Very frequent (present in 80%-99% of cases)
Anophthalmia	Very frequent (present in 80%-99% of cases)
Atrial septal defect	Very frequent (present in 80%-99% of cases)
Bilateral single transverse palmar creases	Very frequent (present in 80%-99% of cases)
Cleft palate	Very frequent (present in 80%-99% of cases)
Cognitive impairment	Very frequent (present in 80%-99% of cases)
Cystic hygroma	Very frequent (present in 80%-99% of cases)
Hydrops fetalis	Very frequent (present in 80%-99% of cases)
Hypotelorism	Very frequent (present in 80%-99% of cases)
Intellectual disability, severe	Very frequent (present in 80%-99% of cases)
Intrauterine growth retardation	Very frequent (present in 80%-99% of cases)
Low-set ears	Very frequent (present in 80%-99% of cases)
Malar flattening	Very frequent (present in 80%-99% of cases)
Median cleft lip	Very frequent (present in 80%-99% of cases)
Microphthalmia	Very frequent (present in 80%-99% of cases)
Muscular hypotonia	Very frequent (present in 80%-99% of cases)
Neurological speech impairment	Very frequent (present in 80%-99% of cases)
Patent ductus arteriosus	Very frequent (present in 80%-99% of cases)
Postaxial hand polydactyly	Very frequent (present in 80%-99% of cases)
Seizures	Very frequent (present in 80%-99% of cases)
Severe global developmental delay	Very frequent (present in 80%-99% of cases)
Ventricular septal defect	Very frequent (present in 80%-99% of cases)
Abnormal lung lobation	Frequent (present in 30%-79% of cases)
Abnormality of female internal genitalia	Frequent (present in 30%-79% of cases)
Abnormality of the antihelix	Frequent (present in 30%-79% of cases)
Abnormality of the eyelashes	Frequent (present in 30%-79% of cases)
Abnormality of the helix	Frequent (present in 30%-79% of cases)
Abnormality of the middle ear	Frequent (present in 30%-79% of cases)
Abnormality of the retinal vasculature	Frequent (present in 30%-79% of cases)
Abnormality of the ribs	Frequent (present in 30%-79% of cases)
Abnormality of the teeth	Frequent (present in 30%-79% of cases)
Abnormality of the ureter	Frequent (present in 30%-79% of cases)
Abnormality of vision	Frequent (present in 30%-79% of cases)
Aplasia/Hypoplasia of the iris	Frequent (present in 30%-79% of cases)
Arnold-Chiari malformation	Frequent (present in 30%-79% of cases)
Calvarial skull defect	Frequent (present in 30%-79% of cases)
Capillary hemangiomas	Frequent (present in 30%-79% of cases)
Cataract	Frequent (present in 30%-79% of cases)
Cryptorchidism	Frequent (present in 30%-79% of cases)
Deeply set eye	Frequent (present in 30%-79% of cases)
Displacement of the external urethral meatus	Frequent (present in 30%-79% of cases)
Hernia	Frequent (present in 30%-79% of cases)
High, narrow palate	Frequent (present in 30%-79% of cases)
Hydronephrosis	Frequent (present in 30%-79% of cases)
Iris coloboma	Frequent (present in 30%-79% of cases)
Kyphosis	Frequent (present in 30%-79% of cases)
Long philtrum	Frequent (present in 30%-79% of cases)
Multiple renal cysts	Frequent (present in 30%-79% of cases)
Narrow chest	Frequent (present in 30%-79% of cases)
Optic atrophy	Frequent (present in 30%-79% of cases)
Preauricular pit	Frequent (present in 30%-79% of cases)
Preauricular skin tag	Frequent (present in 30%-79% of cases)
Scoliosis	Frequent (present in 30%-79% of cases)
Sensorineural hearing impairment	Frequent (present in 30%-79% of cases)

Last updated: 5/8/2017

Cause Cause

Most cases of trisomy 13 are caused by random events during the formation of eggs or sperm in healthy parents (prior to conception). Trisomy 13 is typically due to having three full copies of chromosome 13 in each cell in the body, instead of the usual two copies. This is referred to as complete trisomy 13 or full trisomy 13. The extra genetic material present disrupts the normal course of development, causing the characteristic features of the disorder.

Trisomy 13 can also occur when part of chromosome 13 becomes attached (translocated) to another chromosome during the formation of eggs or sperm, or very early in fetal development. This is referred to as translocation trisomy 13. People with this type of trisomy 13 have the normal two normal copies of chromosome 13, plus an extra copy of chromosome 13 that is attached to another chromosome. Translocation trisomy 13 can be inherited. Approximately 20% of cases of trisomy 13 are caused by translocation trisomy 13.

In rare cases, only part of chromosome 13 is present in three copies in each cell (rather than the full chromosome); this is called partial trisomy 13. In other rare cases, a person has an extra copy of chromosome 13 in only some of the body's cells; this is called mosaic trisomy 13. The severity of mosaic trisomy 13 depends on the type and proportion of cells that have the extra chromosome.^[4]^[5]

Last updated: 4/25/2016

Inheritance Inheritance

Most cases of trisomy 13 are not inherited and result from random events during the formation of eggs and sperm in healthy parents. An error in cell division called nondisjunction results in an egg or sperm cell with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra copy of chromosome 13. If one of these contributes to the genetic makeup of a child, the child will have an extra chromosome 13 in each cell of the body.^[4]

For a woman who has never had a pregnancy or child with a trisomy, the risk to have a pregnancy with a chromosome abnormality would typically be her age-related risk - the risk increases with maternal age. For a woman who has had an affected pregnancy or child in the past, the recurrence risk is generally quoted as about 1% or the maternal age-related risk - whichever is higher at the time of pregnancy.

On the other hand, translocation trisomy 13 can be inherited. An unaffected parent can have a rearrangement of genetic material between chromosome 13 and another chromosome. These rearrangements are called balanced translocations because there is no extra or missing genetic material from chromosome 13. A person with a balanced translocation involving chromosome 13 has an increased chance of passing extra material from chromosome 13 to his/her children.^[4]

People interested in learning about their personal risk to have a child with a chromosome abnormality should speak with their health care provider or a genetics professional.

Last updated: 4/25/2016

Diagnosis Diagnosis

While most cases of trisomy 13 occur randomly, a few cases are due to the presence of a translocation involving chromosome 13 in a parent. Parents who are at risk to have a translocation due to their family history can have a blood test called a karyotype, which can determine if a translocation is present.

Prenatal testing or screening (such as maternal blood screening, fetal ultrasound, chorionic villus sampling, or amniocentesis) is also available to determine if a current pregnancy is at risk for, or is affected by, trisomy 13 or other chromosome disorders.

People with a family history of trisomy 13 who are interested in learning about genetic screening or testing for themselves or family members are encouraged speak with a genetic counselor or other genetics professional.

Last updated: 3/17/2016

Treatment Treatment

Treatment for trisomy 13 depends on the affected person's signs and symptoms, and is generally symptomatic and supportive.^[3] Surgeries are generally withheld for the first few months of life because of the high mortality rate associated 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.^[6]

Last updated: 9/3/2015

Prognosis Prognosis

Trisomy 13 involves multiple abnormalities, many of which are life-threatening. More than 80% of children with trisomy 13 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.^[6]

Last updated: 9/3/2015

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Research Research

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

ClinicalTrials.gov lists trials that are studying or have studied Trisomy 13. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Organizations Organizations

Nonprofit support and advocacy groups bring together patients, families, medical professionals, and researchers. These groups often raise awareness, provide support, and develop patient-centered information. Many are the driving force behind research for better treatments and possible cures. They can direct people to research, resources, and services. Many groups also have experts who serve as medical advisors. Visit their website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

Chromosome Disorder Outreach
PO Box 724
Boca Raton, FL 33429
Telephone: 561-395-4252
E-mail: info@chromodisorder.org
Website: http://www.chromodisorder.org
Hope For Trisomy
PO Box 921
Springtown, TX 76082
Toll-free: 866-977-6637
E-mail: info@trisomyhelp.org
Website: http://www.hopefortrisomy.org
Support Organization for Trisomy 18, 13, and Related Disorders (SOFT)
c/o Barb Vanherreweghe
2982 South Union Street
Rochester, NY 14624
Toll-free: 800-716-SOFT (7638)
Telephone: 585-594-4621
E-mail: barbsoft@rochester.rr.com
Website: http://www.trisomy.org/index.php
Unique – Rare Chromosome Disorder Support Group
G1, The Stables
Station Road West
Surrey
RH8 9EE
United Kingdom
Telephone: +44 (0)1883 723356
E-mail: info@rarechromo.org
Website: http://www.rarechromo.org

Do you know of an organization? Send us your suggestions.

Living With Living With

Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.

Financial Resources

The Social Security Administration has included this condition in their Compassionate Allowances Initiative. This initiative speeds up the processing of disability claims for applicants with certain medical conditions that cause severe disability. More information about Compassionate Allowances and applying for Social Security disability is available online.

Learn More Learn More

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

Genetics Home Reference (GHR) contains information on Trisomy 13. This website is maintained by the National Library of Medicine.
MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

In-Depth Information

Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
PubMed is a searchable database of medical literature and lists journal articles that discuss Trisomy 13. Click on the link to view a sample search on this topic.

GARD Answers GARD Answers

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

I lost a child due to trisomy 13. I have two other children who are both healthy. Is it possible to determine by testing if the disease was caused by translocation or if it was a random occurrence? I am wondering if when they are older I should have my children tested? See answer
I have a Robertsonian translocation 13;14. My husband and I just had our trisomy 13 baby boy pass at 24 weeks gestation. My question is, does the type of trisomy 13 a baby has correlate with how long it will live in utero? For example, does full trisomy 13 have a better chance of survival than translocation trisomy 13? Or do they all have an equal prognosis? See answer
If we had a fetus that terminated due to trisomy 13, and we took the karyotype test and the mother was determined to be a carrier of the Robertsonian translocation (or other translocation), what are the chances another pregnancy would result in a trisomy 13 baby? See answer
I previously had a pregnancy affected by trisomy 13. What is the chance of this happening again in a future pregnancy? Should my partner and I get checked for anything in particular? See answer
Can trisomy 13 happen in a fetus because the mother had a chest X-ray early in pregnancy? Can a father taking an antidepressant or an anxiety prescription contribute to the reason a baby has a trisomy? Thank you for any info you could give us. See answer
Is there any genetic link between trisomy 13, dextrocardia with situs inversus, and Hirschsprung's disease? I have had children affected with each of these conditions. What are the chances of having more children affected with these conditions in the future? See answer
Are there treatments for trisomy 13? What is the prognosis? What is life like for those who have this condition? See answer

Have a question? Contact a GARD Information Specialist.

References References

Trisomy 13 Syndrome. National Organization for Rare Disorders (NORD). 2007; http://rarediseases.org/rare-diseases/trisomy-13-syndrome/.
Trisomy 13. Genetics Home Reference (GHR). November 2013; http://ghr.nlm.nih.gov/condition/trisomy-13.
Haldeman-Englert C. Trisomy 13. MedlinePlus. September 2013; http://www.nlm.nih.gov/medlineplus/ency/article/001660.htm.
Trisomy 13. Genetics Home Reference. November 2013; http://ghr.nlm.nih.gov/condition/trisomy-13.
Robert L. Nussbaum, Roderick R. McInnes, Huntington F. Willard. Thompson & Thompson Genetics In Medicine. Philadelphia, PA: Saunders Elsevier; 2007; 7:75-95.
Best RG, Stallworth J. Patau Syndrome. eMedicine. 2007; http://emedicine.medscape.com/article/947706-overview. Accessed 10/13/2009.