Trisomy 13 (Pätau syndrome)

By | June 10, 2022

Trisomy 13, also known as Patau syndrome, is a rare genetic disorder in which the chromosome 13 occurs three times instead of the usual two. It leads to a variety of different diseases and physical characteristics, most of which lead to death in early childhood. After Down syndrome and trisomy 18, trisomy 13 is one of the most well-known triple deviations.

What is trisomy 13?

A person with trisomy 13 has three copies of chromosome 13. It therefore has 47 instead of 46 chromosomes. There are different types of Patau syndrome.

This depends on whether all cells of the organism are affected by trisomy 13 or only a part. The severity of the defects resulting from the trisomy varies. It includes growth disorders as well as extra fingers or toes or facial deformities. For cryptosporidiosis definition and meaning, please visit

If trisomy 13 occurs, the life expectancy of the affected child is drastically reduced. Only a few reach an age of more than 10 years. Most children with trisomy 13 die within weeks or months of birth.


The causes of trisomy 13 lie primarily in the deviating chromosome division. This does not yet explain how this deviation occurs. There are indications that the occurrence of trisomy 13 could be linked to the increased age of the child’s mother.

Depending on the type of trisomy 13, there are already indications of a form of trisomy 13 in the mother’s genome. The symptoms of Patau syndrome are caused by the surplus chromosome in different degrees. They are least pronounced in mosaic trisomy 13. In this variant, only some of the cells fail to separate the pairs of chromosomes and form three chromosomes in one cell.

The course of partial trisomy 13, in which the chromosome 13 is only partially changed in the cells of the embryo during pregnancy, is similarly weakened.

Symptoms, Ailments & Signs

The disease causes numerous symptoms, both in appearance and in the internal organs. The joint occurrence of three signs is considered characteristic. The first is cleft lip and palate, in which a cleft runs through the upper jaw, upper lip, and palate. Colloquially, this malformation is called harelip. The second sign is microcephaly (small head) and micropthalmia (small eyes).

The small head has an abnormal skull shape and causes reduced brain growth. The small eyes are often only reduced, there may be ametropia or blindness. The merging of the two eyes into one is also possible (cyclopy).

The third symptom of the triple complex is extra fingers or toes ( polydactyly ). Usually there is a sixth joint on the hands or feet, so that twelve fingers or twelve toes are created. In addition to these typical signs, the heart can also be malformed.

A ventricular septal defect, in which there is damage to the septum between the chambers of the heart, often occurs. They can cause heart enlargement and pulmonary hypertension. The ears are exceptionally low set and the nose is flat or absent. Furthermore, malformations of the cranial nerves, the brain, the kidneys, the bladder, the genitals, the blood vessels and the skeleton are among the symptoms of the disease.

Diagnosis & History

Patau syndrome can already be recognized during pregnancy. In prenatal diagnostics, the gynecologist examines deviations in the development of the fetus. If he finds special features that are particularly characteristic of Patau syndrome, a chromosome analysis follows, as is also done when Down syndrome is suspected.

The indications of Patau syndrome include, in particular, cardiac defects in the fetus or developmental disorders and deviations in the amount of amniotic fluid in the pregnant woman. The prognosis for a child born with trisomy 13 is poor.

Mortality is very high in the first few weeks of life. The malformations are often life-threatening because they affect not only the extremities but also the internal organs such as the heart and kidneys. Trisomy 13 is considered a medical reason for termination of pregnancy.


Trisomy 13 generally leads to a number of different malformations and malformations on the affected person’s body. Patients also suffer from serious growth and development disorders. Immediately after birth, the children are severely underweight and suffer from brain development disorders.

This leads to mental retardation and severe limitations in everyday life. Most of those affected are dependent on the help of other people in their everyday life due to trisomy 13. In some cases, the condition also causes those affected to have six fingers. Especially in childhood, the disease can lead to bullying or teasing due to the deformities and thus also cause psychological problems.

As a rule, the parents and relatives of trisomy 13 also suffer from severe psychological problems. Due to the malformations of the internal organs, the life expectancy of the child is also significantly reduced. Since a causal treatment of the syndrome is not possible, only the symptoms are treated. There are no particular complications. The diagnosis of trisomy 13 often leads to termination of the pregnancy.

When should you go to the doctor?

In the case of trisomy 13, the person affected must definitely contact a doctor. Self-healing is not possible with this disease, so medical treatment must always be carried out. The earlier the disease is recognized and treated, the better the further course is in most cases. In most cases, however, the disease leads to the death of the affected person in childhood.

Therefore, the parents and relatives in particular are dependent on psychological treatment so that there is no depression or other mental upsets. A doctor should be consulted for trisomy 13 if the person affected suffers from a facial deformity. The head of the affected person is usually very small, and the eyes are also significantly smaller. Furthermore, a malformation of the heart can indicate the disease and must be examined by a doctor.

The disease can be detected by a pediatrician. However, further treatment is carried out by a specialist. If the parents wish to have another child, genetic counseling should also be carried out to prevent the recurrence of trisomy 13.

Treatment & Therapy

Treatment for trisomy 13 depends on the defects that are present in the individual case. Due to the high mortality rate, the symptoms are usually only alleviated.

If children with trisomy 13 are born alive, medical care must always be arranged individually. Malformations in the form of a cleft lip and palate often occur in Patau syndrome. Increasing the ability to speak is one of the necessary therapies. In addition, there is movement therapy and social and psychological support for parents who are involved in caring for the children.

However, surgical interventions to correct the malformations in Patau syndrome are still rare. However, there has been a change in medical treatment. As a result, the life expectancy of children suffering from trisomy 13 increases, even if it is not yet to be assessed as particularly high.


If trisomy 13 is detected in good time before the birth, the question of terminating the pregnancy often arises. However, real prevention of trisomy 13 is not possible because the parents cannot influence it. On the other hand, the probability of a recurrence of trisomy 13 in a new pregnancy is only slightly increased.


Since the life expectancy of children with trisomy 13 is low, the psychological care of the parents and other family members plays an important role in aftercare. With sensitive and professional support, the difficult situation can be better managed by all those involved.

The care of parents and siblings should not stop even after the death of the child concerned. How long the follow-up care makes sense cannot be determined in general terms. It depends on the individual family situation as well as on the wishes of the relatives. The primary aim of medical aftercare is to offer children with Patau syndrome the best possible quality of life.

Existing physiological defects should be examined regularly. In this way, it can be determined at an early stage if the patient’s condition is deteriorating. If a woman becomes pregnant again after giving birth to a child with trisomy 13, the risk of this gene defect reappearing is only slightly increased. Special measures are therefore not required.

However, many families seek human genetic counseling to feel more secure. During a subsequent pregnancy, repeated trisomy 13 can be ruled out by testing the amniotic fluid. However, those involved should always bear in mind that this examination increases the risk of a miscarriage.

You can do that yourself

It is important to know that with trisomy 13 not only the child is in the foreground. The (expectant) parents must also be seen as suffering in this difficult situation. Psychological support may be needed in order to better cope with dealing with the disease. In many medical institutions and special clinics, parents are therefore provided with a psychologist to accompany them. This makes it easier for many to enjoy the time they can have with their child.

But as soon as trisomy 13 is diagnosed, many parents suffer from restlessness, sleep disorders and deep sadness. However, so that you can still enjoy the limited time with your baby, small home remedies can bring some relief for some. These include medicinal plants and herbs that have a calming effect. Lavender is particularly well known. Essential oils can also provide a bit of relaxation.

Many parents feel good knowing they are not alone in their situation. There are various exchange networks on the Internet. Here you can find testimonials about the pregnancy and the time with the child. The association for family self-help LEONA eV offers not only a wide range of information but also a network that enables exchange with other affected parents.

Trisomy 13 (Pätau syndrome)