Trisomy 13
Patau syndromeTrisomy 13 (also called Patau syndrome) is a genetic disorder in which a person has 3 copies of genetic material from chromosome 13, instead of the usual 2 copies. Rarely, the extra material may be attached to another chromosome (translocation).
Chromosome
Chromosomes are structures found in the center (nucleus) of cells that carry long pieces of DNA. DNA is the material that holds genes. It is the bu...
Read Article Now Book Mark ArticleCauses
Trisomy 13 occurs when extra DNA from chromosome 13 appears in some or all of the body's cells.
- Trisomy 13: the presence of an extra (third) chromosome 13 in all of the cells.
- Mosaic trisomy 13: the presence of an extra chromosome 13 in some of the cells.
- Partial trisomy 13: the presence of a part of an extra chromosome 13 in the cells.
The extra material interferes with normal development.
Trisomy 13 occurs in about 1 out of every 10,000 newborns. Most cases are not passed down through families (inherited). Instead, the events that lead to trisomy 13 occur in either the sperm or the egg that forms the fetus.
Symptoms
Symptoms include:
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Cleft lip or palate
Cleft lip or palate
Cleft lip and palate are birth defects that affect the upper lip and the roof of the mouth.
Read Article Now Book Mark Article - Clenched hands (with outer fingers on top of the inner fingers)
- Close-set eyes -- eyes may actually fuse together into one
- Decreased muscle tone
- Extra fingers or toes (polydactyly)
Polydactyly
Polydactyly is a condition in which a person has more than 5 fingers per hand or 5 toes per foot.
Read Article Now Book Mark Article - Hernias: umbilical hernia, inguinal hernia
Umbilical hernia
An umbilical hernia is an outward bulge in the area around the belly button. It occurs when internal organs or the abdominal lining bulges through t...
Read Article Now Book Mark ArticleInguinal hernia
A hernia is a sac formed by the lining of the abdominal cavity (peritoneum). The sac comes through a hole or weak area in the strong layer of the be...
Read Article Now Book Mark Article - Hole, split, or cleft in the iris (coloboma)
Coloboma
Coloboma of the iris is a hole or defect of the iris of the eye. Most colobomas are present since birth (congenital).
Read Article Now Book Mark Article - Low-set ears
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Intellectual disability, severe
Intellectual disability
Intellectual disability is a condition diagnosed before age 18 that includes below-average intellectual function and a lack of skills necessary for d...
Read Article Now Book Mark Article - Scalp defects (missing skin)
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Seizures
Seizures
A seizure is the physical changes in behavior that occurs during an episode of specific types of abnormal electrical activity in the brain. The term ...
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Single palmar crease
Single palmar crease
A single palmar crease is a single line that runs across the palm of the hand. People most often have 3 creases in their palms. The crease is most o...
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Skeletal (limb) abnormalities
Skeletal (limb) abnormalities
Skeletal limb abnormalities refers to a variety of bone structure problems in the arms or legs (limbs).
Read Article Now Book Mark Article - Small eyes
- Small head (microcephaly)
Microcephaly
Microcephaly is a condition in which a person's head size is much smaller than that of others of the same age and sex. Head size is measured as the ...
Read Article Now Book Mark Article - Small lower jaw (micrognathia)
Micrognathia
Micrognathia is a term for a lower jaw that is smaller than normal.
Read Article Now Book Mark Article - Undescended testicle (cryptorchidism)
Cryptorchidism
Undescended testicle occurs when one or both testicles fail to move into the scrotum before birth.
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Exams and Tests
The infant may have a single umbilical artery at birth. There are often signs of congenital heart disease, such as:
Congenital heart disease
Congenital heart disease (CHD) is a problem with the heart's structure and function that is present at birth.
Read Article Now Book Mark Article- Abnormal placement of the heart toward the right side of the chest instead of the left
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Atrial septal defect
Atrial septal defect
Atrial septal defect (ASD) is a heart defect that is present at birth (congenital). As a baby develops in the womb, a wall (septum) forms that divide...
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Patent ductus arteriosus
Patent ductus arteriosus
Patent ductus arteriosus (PDA) is a condition in which the ductus arteriosus does not close. The word "patent" means open. The ductus arteriosus is ...
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Ventricular septal defect
Ventricular septal defect
Ventricular septal defect is a hole in the wall that separates the right and left ventricles of the heart. Ventricular septal defect is one of the m...
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Gastrointestinal x-rays or ultrasound may show rotation of the internal organs.
MRI or CT scans of the head may reveal a problem with the structure of the brain. The problem is called holoprosencephaly. It is the joining together of the 2 sides of the brain.
Chromosome studies show trisomy 13, trisomy 13 mosaicism, or partial trisomy. Rarely, the extra material may be attached to another chromosome (translocation).
Chromosome studies
Karyotyping is a test to examine chromosomes in a sample of cells. This test can help identify genetic problems as the cause of a disorder or diseas...
Read Article Now Book Mark ArticleTreatment
There is no specific treatment for trisomy 13. Treatment varies from child to child and depends on the specific symptoms.
Support Groups
More information and support for people with Trisomy 13 condition and their families can be found at:
- Support Organization for Trisomy 18, 13 and Related Disorders (SOFT): trisomy.org
- Hope for Trisomy 13 and 18: www.hopefortrisomy13and18.org
Outlook (Prognosis)
More than 90% of children with trisomy 13 die in the first year.
Possible Complications
Complications begin almost immediately. Most infants with trisomy 13 have congenital heart disease.
Complications may include:
- Breathing difficulty or lack of breathing (apnea)
- Deafness
- Feeding problems
- Heart failure
- Seizures
- Vision problems
When to Contact a Medical Professional
Contact your health care provider if you have had a child with trisomy 13 and you plan to have another child. Genetic counseling can help families understand the condition, the risk of inheriting it, and how to care for the person.
Prevention
Trisomy 13 can be diagnosed before birth by amniocentesis with chromosome studies of the amniotic cells.
Amniocentesis
Amniocentesis is a test that can be done during pregnancy to look for certain problems in the developing baby. These problems include:Birth defectsG...
Read Article Now Book Mark ArticleParents of infants with trisomy 13 that is caused by a translocation should have genetic testing and counseling. This may help them be aware of the chances of having another child with the condition.
References
Bacino CA, Lee B. Cytogenetics. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 98.
Madan-Khetarpal S, Arnold G, Ortiz D. Genetic disorders and dysmorphic conditions. In: Zitelli BJ, McIntire SC, Nowalk AJ, Garrison J, eds. Zitelli and Davis' Atlas of Pediatric Physical Diagnosis. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 1.
National Center for Advancing Translational Sciences. Genetic and Rare Diseases Information Center website. Trisomy 13. rarediseases.info.nih.gov/diseases/7341/trisomy-13. Updated February 2023. Accessed October 17, 2023.
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Polydactyly - an infant's hand - illustration
Extra digits may be present as an isolated finding, or they may occur as part of a syndrome, in which case other abnormalities are usually present.
Polydactyly - an infant's hand
illustration
Review Date: 9/18/2023
Reviewed By: Anna C. Edens Hurst, MD, MS, Associate Professor in Medical Genetics, The University of Alabama at Birmingham, Birmingham, AL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.