Patau syndrome

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Classification according to ICD-10
Q91.4 Trisomy 13, meiotic non-disjunction
Q91.5 Trisomy 13, Mosaic ( Mitotic Non-Disjunction)
Q91.6 Trisomy 13, translocation
Q91.7 Patau syndrome, unspecified
ICD-10 online (WHO version 2019)

The Patau Syndrome , including trisomy 13 , ( Syn. : Patau syndrome , Bartholin -Patau syndrome and D1 trisomy ) is a by tripling ( trisomy ) of genetic material of chromosome 13 caused disability based on a genome mutation . The syndrome is currently one of those chromosomal aberrations that are associated with above-average child mortality and the number of miscarriages and stillbirths .

History and discovery

The physical characteristics of children with this syndrome were first described in the medical literature in 1657 by the Dane Erasmus Bartholin . The German-American human geneticist Klaus Pätau discovered in 1960 that these are consequences of trisomy 13 . The name of the syndrome goes back to these two scientists, whereby the synonym Pätau syndrome is given quantitative preference over Bartholin-Pätau syndrome in the literature .

Frequency of occurrence

The Patau syndrome is one of the comparatively rare chromosome peculiarities and occurs on average in 1 in 15,000 to 1 in 4,000 children. This makes it the third most common trisomy among live-born children after trisomy 21 ( Down syndrome ) and trisomy 18 ( Edwards syndrome ).

causes

The cause of the Patau syndrome is a chromosome peculiarity in which additional genetic material from chromosome 13 is present. The following types are distinguished:

Free trisomy 13
This most common form of the syndrome occurs when one of the germ cells contains an extra chromosome 13. This can happen if, during the formation of the egg cells or sperm cells, the chromosome pair 13 is not separated as usual and like the other chromosome pairs ( meiotic non-disjunction ). With a few exceptions, such an event occurs randomly. The frequency of occurrence of free trisomy 13 is associated with an increased age of the biological mother, although every woman of childbearing potential at any age can expect a child with trisomy 13. When free trisomy 13 is present, three instead of two chromosomes 13 are present in all body cells. The karyotype is therefore 47, XX, + 13 or 47, XY, + 13.
Mosaic trisomy 13th
In genetics, a mosaic is understood to mean the presence of several karyotypes within an organism. In mosaic trisomy 13, a trisome and a disome cell line coexist. The chromosome pairs stay together only during the first cell divisions after fertilization ( mitotic non-disjunction ). The later this process takes place, the fewer cells are trisome. Depending on the proportion of disome cells, the symptoms of Patau's syndrome are sometimes less pronounced. People with mosaic trisomy 13 have both body cells with 46 and body cells with 47 chromosomes. The karyotype is therefore 46XX / 47, XX, + 13 or 46XY / 47, XY, + 13.
Partial trisomy 13
In partial (= partial, partial) trisomy 13, chromosomes 13 are present in duplicate in all body cells, as usual, but part of one of the two chromosomes 13 is doubled, which means that one of chromosomes 13 is slightly longer than the other. The hereditary information in this section is therefore available three times. Usually, in people with partial trisomy 13, features of the syndrome are less pronounced, depending on the trisomal chromosome segment, although this should not be generalized, but always viewed on a case-by-case basis.
Translocation trisomy 13
In rare cases, the additional chromosome material from chromosome 13 has attached itself to another chromosome, usually to an acrocentric number 14, 15, 21 or 22. This change in location of chromosomes is called translocation in genetics , and the shape of trisomy 13 is accordingly Called translocation trisomy 13. The translocation chromosome is the product of a fusion (fusion) of the long arm of chromosome 13 and the long arm of one of the above acrocentric chromosomes. In exceptional cases the translocation chromosome consists of two long arms of chromosome 13. These types of translocation belong to the group of Robertson translocations . The karyotype of a translocation trisomy 13 is depending on which chromosome one of the number 13 has attached z. B. 46, XX, t (14; 13) or 46, XY, t (14; 13). Here the additional 13th chromosome has attached to one of the two chromosomes of number 14.

In translocation trisomy 13, one parent can be the "carrier" in some cases . A balanced translocation of a 13th chromosome can be detected in such a parent . The karyogram then shows 45 instead of 46 individual chromosomes because two chromosomes have joined together. Since no relevant genetic material is lost or added to this peculiarity, the genetic information is in equilibrium (= balanced ) and the person does not experience trisomy 13. However, the likelihood that the person concerned will father a child with a translocation trisomy 13 is increased. If both chromosomes 13 have connected with each other in a balanced translocation in one of the parents, a child conceived by the person concerned always has a translocation trisomy 13/13. However, this is extremely rare.

Symptoms

With a few exceptions, signs of trisomy 13 always occur in combination with each other in a child, even if not all children show all characteristics at the same time or to the same extent.

Common features before birth

In the course of the steadily developing possibilities of prenatal examinations ( prenatal diagnosis ), some peculiarities have been documented over time, which can very often be detected in babies with Patau syndrome during pregnancy. Only in very rare exceptional cases are there any signs of trisomy 13 in the child during prenatal examinations. The indicators that can indicate the presence of a trisomy 13 in the unborn child, particularly in combination with one another , and which can sometimes be recognized by means of ultrasound or blood tests , include, for example:

Common features after childbirth

In many children, other peculiarities can be determined after birth. Not all children show all characteristics to the same extent. The most common features include:

diagnosis

Pätau syndrome can be suspected prenatally based on certain signs (see above ) and after birth (postnatal) based on external characteristics (suspected diagnosis). During pregnancy it is possible to diagnose trisomy 13 in the unborn child with a high degree of certainty by means of a chromosome analysis. The material required for this analysis must contain cells from the unborn child and is obtained by an invasive (e.g. chorionic villus sampling or amniocentesis ) or non-invasive examination (using maternal blood). A prenatal chromosome analysis is open to all women in Germany and must be offered to women aged 35 and over.

A chromosome examination must follow for an almost 100% reliable diagnosis after the birth. By chromosome analysis of lymphocytes of the blood not only the diagnosis can be confirmed, but also the type of trisomy 13 (Free trisomy 13, translocation trisomy 13, mosaic trisomy 13) are detected.

Differential diagnosis

The following are to be distinguished:

treatment

Trisomy 13 cannot be cured causally. Therapy is therefore limited to treating the individual physiological defects and other symptoms. This can be, for example, surgical interventions as well as therapeutic measures such as physiotherapy or speech therapy.

forecast

Many of the children affected die before they are born. Children who survive pregnancy and childbirth have so far mostly had a reduced life expectancy, although it has meanwhile been shown that the life span depends heavily on which peculiarities (especially in the physical-organic area) are present in them in which extent and whether they are after birth receive adequate medical and social treatment.

Most children who survive pregnancy and childbirth so far die in the first twelve months after birth. Girls often survive longer than boys: an average of 3 in 10 girls with trisomy 13 reach the age of five and 1 in 10 reach the age of ten, while boys generally do not survive the first five years after birth. The most common causes of death are heart failure, cardiovascular failure, respiratory failure and pneumonia.

In children with mosaic trisomy 13, the symptoms are usually less pronounced, depending on the proportion of disome cells, and their life expectancy is often positively influenced by this.

Repetition probability

Trisomy 13 cannot be brought about by anything and is not causally curable. A general prophylaxis (prevention) is not possible. The option of (late) abortion for medical reasons can at most prevent the live birth of the child after the confirmed prenatal diagnosis. For a woman who was already pregnant with a child with free trisomy 13, the probability of having another child with Patau syndrome is slightly (1%) higher than the probability for her corresponding age group. The slight increase results in particular from the possibility of a mosaic in the parental germ cells, which cannot be ruled out .

The same applies to a translocation trisomy 13 if the chromosome findings of the parents are normal. However, there are indications of age dependency. If a balanced translocation of a 13th chromosome is detected in one of the parents , the probability for children with the translocation type of the syndrome is theoretically 25%. However, empirical values ​​are far below that, since with chromosomal imbalance the fetus often dies prematurely and often unnoticed by the pregnant woman. However, the probability of trisomy 13 in a child is 100% if the two chromosomes 13 of a pair are connected to one another in the balanced translocation of one parent (translocation 13/13). This is extremely rare.

Individual evidence

  1. ↑ emedicine

literature

  • Ann M. Barnes; John C. Carey: Care of the infant and child with trisomy 18 or 13. Medical problems, reported treatments and milestones. SOFT Distribution Center, La Fox IL 1996.
  • Burkhard Cicholas: Heart defects in patients with trisomy 13. Münster 1985 (Münster, University, dissertation, 1985).
  • AC Duarte, AIC Menezes, ES Devens, JM Roth, GL Garcias, MG Martino-Roth: Patau syndrome with a long survival. A case report. In: Genetics and molecular research. Vol. 3, No. 2, 2004, ISSN  1676-5680 , pp. 288-292, online .
  • Ruth Höffkes-Göhl: Anomalies of the metopic suture in trisomy 13. Erlangen 1985 (Erlangen / Nürnberg, University, dissertation, 1985).
  • Christine Piper: Follow-up study for 4 common chromosome aberrations. Cri-du-chat syndrome, Wolf-Hirschhorn syndrome, trisomy 13, trisomy 18. Frankfurt am Main 2002 (Frankfurt am Main, University, dissertation, 2002).
  • Sigrid Köck-Sauvagerd: Home care for children with an infant with trisomy 13 (Patau syndrome). In: Pediatric Nurse. 20th year, No. 11, 2001, ISSN  0723-2276 , pp. 459ff. (PDF; 389 kB).
  • Klaus Sarimski: Developmental Psychology of Genetic Syndromes. 3rd, completely revised and expanded edition. Hogrefe, Göttingen et al. 2003, ISBN 3-8017-1764-X .
  • Kornelia Schmidt: Partial trisomy 13 and complete trisomy 13 in comparison. Aachen 1979 (Aachen, Technical University, dissertation, 1979).
  • Carol M. Stenson, Steven E. Daley, Patricia A. Farmer: Trisomy 13. A guidebook for families. University of Nebraska Medical Center - Meyer Rehabilitation Institute, Omaha NE 1992.

See also