The Down syndrome is a congenital coincidence of a mental disability and physical malformations . The cause is a fault in the genetic make-up of the affected person ( genome mutation , chromosome aberration or aneuploidy ). In this case, it is chromosome 21 (chromosome are components of cells on which genetic information is stored) or parts thereof in triplicate instead of duplicate. This chromosome disorder is therefore called trisomy 21 (from ancient Greek τρία tría, German 'three, three things' and σῶμα sôma, German 'body'; here: chromosome body No. 21, as the carrier of the genetic information). Chromosomes can be tripled when cells divide in such a way that instead of one chromosome, two chromosomes of the same number enter the germ cell. The fertilized egg cell then has a total of three chromosomes (since another chromosome has been added): One each from the mother and father and an additional one from either the mother or the father.
With increasing age of the mother (especially from the age of 35), the risk of trisomy 21 in the child increases. People with Down syndrome usually have typical physical characteristics and are usually impaired in their cognitive abilities , that is, in their thinking abilities . The malformations and impairments can vary in severity.
The tripling of the corresponding genetic material occurs mostly through incorrect segregation , the lack of divergence of the chromosomes during meiosis (cell nucleus division). The various forms of trisomy 21 either arise spontaneously or can be inherited if the mother already has Down syndrome herself. A translocation trisomy (due to chromosome displacement) can, however, occur more often in families, provided one parent has a predisposition, i.e. a balanced translocation of a 21st chromosome in one parent without the symptoms of Down's syndrome.
According to the current state of research, a clear prenatal (prenatal) diagnosis is possible by examining the fetal chromosomes, which are obtained by amniocentesis (amniotic fluid puncture ) or chorionic villus sampling (placenta puncture ), more rarely by umbilical cord puncture (cordocentesis). Since 2012, blood tests have been used to find and examine traces of fetal genetic material in the mother. The selection made possible by an abortion is ethically controversial.
The name Down syndrome refers to the British doctor and pharmacist John Langdon Down , who first comprehensively described this syndrome in 1866. The name originally chosen by Down was English Mongolian idiocy (mongoloid idiocy, from which the term Mongolism is derived), as he suspected that the syndrome was a regression to a Mongolian tribe, because of the facial features characteristic of Down's syndrome and the shape of the eyes, which was attached to relatives an Asian ethnic group called the "Mongols". In 1965 Mongolia submitted an application to the World Health Organization (WHO) requesting that the term Mongolian Idiocy and its derivatives no longer be used due to the negative and racist occupation. The WHO unanimously accepted this proposal. In 1961, the prestigious British scientific journal was The Lancet at the request of an international group of nineteen recognized geneticists, the description in Down's Syndrome (German: Down syndrome ) amended. The use of the term Mongolism gradually decreased and disappeared in the early 1980s, since then it has only been used in articles on the history of the syndrome. The name Down syndrome is the most common. Trisomy 21 is preferred when the disorder is referred to in conjunction with other chromosomal abnormalities.
Due to the mechanisms behind trisomy 21, it is assumed that there have always been people with Down syndrome. The Tübingen human biologists Alfred Czarnetzki , Nikolaus Blin and Carsten M. Pusch provided the earliest evidence of trisomy 21 to date . They demonstrated the typical symptoms on the skeleton of a woman who died around 2550 years ago near Tauberbischofsheim between the ages of 18 and 20.
The English neurologist and pharmacist John Langdon Down described Down's syndrome, named after him, for the first time scientifically in 1866 as an independent syndrome that can be distinguished from other diseases and disabilities . It was not until 1959, 63 years after Langdon Down's death, that Marthe Gautier , Raymond Turpin and Jérôme Lejeune recognized the genetic cause of the syndrome: They discovered that each cell of the affected people had 47 instead of the usual 46 chromosomes , i.e. a tripling of one chromosome ( Trisomy ) instead of duplication. They couldn't yet tell which chromosome was tripled. Only later was it proven that the 21st chromosome was affected (trisomy 21).
Two chimpanzees - whose chromosome 22 corresponds to human chromosome 21 - were found to develop symptoms similar to those in people with trisomy 21 because of trisomy 22.
Trisomy 21 is not one of the hereditary diseases in the narrower sense.
In 95 percent of all cases, trisomy 21 is caused by an unusual meiosis . Either the homologous chromosomes are not separated ( non-disjunction ) in the first meiosis or the chromatids are not separated in the second meiosis.
According to the doctrine, a maldistribution of chromosome 21 during egg cell formation is related to maternal age and to the frequency and distribution of recombination events . In contrast, external causes such as ionizing radiation are controversial. In 1987 the Berlin human geneticist Karl Sperling sparked controversy with his thesis that the Chernobyl reactor accident in 1986 caused an unusually high number of Down syndrome cases in Germany in the following year. Despite follow-up studies and publications, his conclusions were “violently contradicted” and are not recognized as the current state of research.
Forms of trisomy 21
There are four types of trisomy 21:
Free trisomy 21
The free trisomy 21 arises due to meiotic non-disjunction. About 95 percent of people with Down syndrome have this type, in which chromosome 21 is completely triple in all cells of the body . In principle, however, it is possible that a free trisomy 21 is diagnosed, although a mosaic trisomy 21 (see below) is actually present. In science, it is assumed that only about 70 out of 100 people with Down syndrome have free trisomy 21 and a significantly higher proportion have the mosaic shape, but often not recognized as such in chromosome examinations, but as free trisomy 21 is diagnosed. The karyotype of free trisomy 21 is: 47, XX + 21 or 47, XY + 21.
Translocation trisomy 21
Three to four percent of people with Down syndrome have this type, in which chromosome 21 is completely triple in all body cells, but one of chromosomes 21 has attached to another chromosome. Often to one of the numbers 13, 14, 15 or 22, rarely also to one with the number 21. A chromosome shift is referred to as a translocation in genetics . The karyotype of a translocation trisomy 21 is, for example: 46, XX, t (21; 14) or 46, XY, t (21; 14).
Mosaic Trisomy 21
The mosaic trisomy 21 results from mitotic non-disjunction. One to two percent of people with Down syndrome have this type, in which chromosome 21 is not present three times in all body cells, but rather a cell line with the usual set of chromosomes. The parallel presence of several cell lines is called a mosaic in genetics . The mosaic trisomy 21 arises only after the first cell division of a fertilized egg cell. Due to the presence of two different cell lines, it can in principle happen that a chromosome analysis only examines samples with a trisome chromosome set on the basis of which a free trisomy 21 (see above) would then be diagnosed, even though a mosaic trisomy 21 is present. Some scientists therefore assume that an estimated 30 out of 100 people with Down syndrome have the mosaic shape, but that this is often not recognized as such, but is diagnosed as free trisomy 21. In some people with mosaic trisomy 21, the characteristics of the syndrome are less pronounced, depending on the proportion of disome cells, although this should not be generalized, but always viewed on a case-by-case basis. The karyotype of the mosaic trisomy 21 is: 46, XX / 47, XX + 21 or 46, XY / 47, XY + 21.
Partial trisomy 21
This type is extremely rare, only a few hundred cases are known worldwide. In people with partial (= partial, partial) trisomy 21, chromosomes 21 are present in duplicate in all body cells as usual, but part of one of the two chromosomes 21 is doubled, which means that one of chromosomes 21 is slightly longer than the other. The hereditary information in this section is therefore available three times. Partial trisomy 21 plays an important role in research. It is investigated how the trisomy of certain sections and genes on a chromosome 21 is related to the expression of characteristics that are typical of the syndrome, because in people with partial trisomy 21 characteristics of the syndrome are usually less pronounced depending on the trisomal chromosome segment, whereby this should not be generalized, but should always be considered in each individual case. The karyotype of a partial trisomy 21 is e.g. E.g .: 46, XXder (21) (q23.2; q22.11) or 46, XYder (21) (q23.2; q22.11)
About 30,000 to 50,000 people with trisomy 21 live in Germany.
Trisomy 21 is the most common chromosomal aberration in newborns .
Statistical surveys show that the probability of having a child with trisomy 21 increases exponentially with the age of the mother : at the age of 25 it is less than 0.1 percent, at the age of 35 it is 0.3 percent, at the age of 40 at one percent and at the age of 48 at nine percent. This is probably due to the aging of the woman's prenatally formed egg cells, which is associated with an increasing incidence of errors in meiosis .
Depending on the maternal age distribution in a population, the average frequency ( prevalence ) is 0.125 to 0.2 percent, i.e. between about 1: 500 to 1: 800. In Germany, the proportion of expected children with Down's syndrome in 2006 was around 1: 500, i.e. 0.2 percent.
Relationship between age, diagnosis and termination of pregnancy
The prevalence of the development of trisomies in children, which increases sharply with increasing mother's age, is not reflected to the same extent in the number of children actually born with trisomy 21 in the western hemisphere. This is due to the fact that older mothers use prenatal diagnosis significantly more often . If a high probability of trisomy 21 is determined, the mother decides in most cases to terminate the pregnancy .
A statistical survey between 1992 and 1996 showed that about a quarter of the children with trisomy 21 in the age group of 25 to 29 year old mothers and about a third in the age group of 30 to 34 year olds were recorded prenatally . After the diagnosis and consultation, 94.5 percent of the mothers did not carry their child to term.
Another study from 1988 to 1997 registered an overall prenatal detection rate of 53 percent. In the overall group, only 23 percent of the mothers were 35 years of age or older (although 77 percent of them did not have an increased likelihood of trisomy 21 in the child). After the prenatal diagnosis, 90 percent of the mothers did not carry their child to term.
In the summer of 2012, a new non-invasive prenatal test for Down syndrome came on the market. The human geneticist Wolfram Henn sees considerable pressure on expectant mothers: “On the one hand, Down syndrome is becoming even more of a target of prenatal search strategies, which calls into question the acceptance of people born with Down syndrome. On the other hand, there is increasing pressure to make use of prenatal diagnostics with the option of an abortion. It is becoming more and more difficult to confess unconditionally to your future child for personal and religious reasons. ”In many European countries, due to abortions, hardly any children are born with Down's syndrome.
Boys are more often affected than girls ( androtropia ): Dittmann found a value of 53:47, Wilken observed a ratio of 57.2: 42.9 (1974) and 54:46 (2000). So far it has not been clarified what causes this imbalance.
Association with multiple pregnancies
In addition to a familial disposition for multiple pregnancies , the likelihood of having twins or higher-grade multiples increases with the age of the mother. In addition, hormone treatment and reproductive measures to increase fertility are increasing ; here, too, the probability of multiples increases. The connection of these developments with the natural increase in the likelihood of Down syndrome in the advanced age of the child mother means that the birth rate of children with trisomy 21 in multiple constellations also increases. The National Down Syndrome Cytogenetic Register in Great Britain registered a total of 244 pairs of twins in 2003; in 29 pairs of them (11.8 percent) both children had trisomy 21 (one pair was dizygoti: girl / boy). In addition, nine triplets were known, of which one child each had the additional chromosome 21.
The diagnosis of free trisomy 21 due to meiotic non-disjunction is given in the ICD-10 with the code Q90.0 , the mosaic trisomy 21 due to mitotic non-disjunction with Q90.1 , the translocation trisomy 21 with Q90.2 and the Code Q90.9 stands for the unspecified diagnosis of trisomy 21 . The code number O35.1 is given for the care of an expectant mother who is expecting a child with Down syndrome.
Characteristics before birth (prenatal)
Examination of the genetic material
According to the current state of research, a clear diagnosis is only possible by examining the chromosomes themselves, which are conventionally obtained by amniocentesis or chorionic villus sampling , more rarely by umbilical cord puncture ( cordocentesis ). These are invasive interventions, each of which is associated with a different risk of intervention-related miscarriages.
Since 2012, new, non-invasive test procedures have been approved in numerous countries that examine the mother's blood for traces of fetal genetic material and which now respond to trisonomies 21, 18 and 13. According to their own statements, researchers at Stanford University in California succeeded in reproducing cell-free DNA fragments of the mother and fetus from the mother's blood in 2008 and assigning them quantitatively to the 46 human chromosomes . If the blood samples come from pregnant women whose fetuses show a trisomy , the DNA of their respective additional chromosomes is represented in greater quantities in the maternal blood than in unaffected pregnancies. This higher presence could be demonstrated for various chromosome abnormalities - including trisomy 21 - using the new method. It was discussed early on whether such non-invasive methods of prenatal diagnosis would replace other invasive methods ( amniocentesis , chorionic villus sampling ) in a few years or at least severely limit the frequency of invasive procedures.
At the end of 2014, a provider spoke of around 10,000 tests carried out by his company, around half of them on German women. In May 2015, a Swiss newspaper reported that 4500 tests had been carried out on Swiss women to date and that the costs had been taken over by a health insurance company for the first time.
According to the manufacturer, the non-invasive procedures have a very low error rate; however, prenatal diagnosticians recommend confirming a positive diagnosis using one of the conventional, invasive procedures.
The approval of non-invasive procedures has been and is heavily criticized from an ethical point of view. Representatives of the disabled are calling for the tests to be banned because they lowered the inhibition threshold for such examinations and the subsequent termination of pregnancy of such fetuses and, in their opinion, ultimately violated the right to life of disabled people; It also paves the way for further genetic tests on the fetus and the “designer baby”. Proponents, on the other hand, point to about 98% of normal test results - in these cases the test avoids the risks for the fetus and mother associated with invasive methods. Manufacturers' recommendations to use the tests for prenatal trisomy screening in pregnant women of all age groups have fueled the ethical debate, also with regard to the question of whether the tests should be financed by statutory health insurance. The pediatrician Holm Schneider stated that he did not consider it “a step forward to be able to select children 'in time' and 'without risk' by means of non-invasive procedures, but rather a step backwards, for the countercurrent to the efforts towards inclusion in many places”.
Investigation of other evidence
In the course of the steadily developing possibilities of prenatal examinations ( prenatal diagnostics ), some peculiarities have been documented over time that are relatively often found in babies with trisomy 21 and can sometimes be detected by means of ultrasound or blood tests. None of these characteristics occur in any baby with Down syndrome; Most babies only have about one to three features prenatal, and some have none that are pronounced enough to be classified as indicators. In addition, some of the peculiarities are comparatively difficult to recognize or evaluate in terms of their importance in the prenatal phase.
None of the signs are sufficient to diagnose Down syndrome, even if several of these peculiarities occur at the same time. Only the likelihood of Down syndrome in the baby increases. The symbols include, for example:
- Heart defects (vitien)
- a comparatively small baby (growth disorders, often due to heart defects)
- a comparatively small head ( microcephaly / babies with Down syndrome have an average three percent smaller head than regular babies, their brain is smaller and more spherical in shape)
- a comparatively large eye relief ( hypertelorism )
- a comparatively short thigh bone (femur)
- a comparatively short upper arm bone ( humerus )
- Sandal gap / furrow (an increased space between the first and second toe)
- an underdeveloped (hypoplastic) nasal bone ( snub nose , but not a significant marker, as it also depends on ethnic origin)
- an underdeveloped (hypoplastic) or absent (aplastic) middle phalanx ( middle phalanx ) of the fifth finger
- slight bending of the fifth finger in the direction of the ring finger ( camptodactyly ) with simultaneous shortening of tendons and tendon sheaths, which make it impossible to fully extend the respective fingers ( clinodactyly )
- an intestinal obstruction ( duodenal atresia / double-bubble phenomenon)
- echogenic intestinal loops ( echogenic means that an organ, tissue or structure appears bright in the ultrasound image )
- a large amount of amniotic fluid ( polyhydramnios / some babies with Down syndrome drink little or no amniotic fluid)
- White Spots ( golf ball phenomenon , echogenic focus / punctiform, white densities in one of the large chambers of the heart , the so-called ventricles)
- certain hormone concentrations in the blood of the pregnant woman (the hormone values for AFP and E3 are sometimes reduced, but increased for β-hCG / see: triple test )
- a noticeably large accumulation of fluid in the neck area in about 25 out of 100 babies (large neck transparency / neck edema averaging five millimeters thick, sometimes also hygroma colli , less often hydrops fetalis )
- a slight expansion of the renal pelvis calyx system ( pyelectasis / limit value of more than three or four millimeters in diameter, depending on the week of pregnancy)
Postpartum characteristics (postnatal)
After birth, most babies with Down syndrome have various physical characteristics that make what is known as a suspected diagnosis possible. These include B .:
- Brushfield spots (white, light gray, or light yellow speckles on the outside of the iris of the eyes)
- a small sickle-shaped fold of skin at the inner corner of the eye ( epicanthus medialis )
- third fontanel (in some newborn children, in addition to the usual, not yet completely ossified area on the head, there is an additional third fontanel on the seam between the large and small fontanel)
- Lid axes sloping upwards outwards (give the eyes a somewhat almond-shaped appearance)
- Muscle hypotonia (muscle tension is significantly reduced at first, most babies have difficulty sucking, tire more easily, cry less and are quieter than babies without Down syndrome and often have their tongue protruding a bit from their mouth)
- Sandal gap / furrow (an increased space between the first and second toe)
- Four-finger furrow (in approx. 75 out of 100 children)
The internal organic peculiarities that occur in many babies with Down syndrome include:
- Heart defects in 40 to 60 percent of newborns; the most common are the atrial septal defect (ASD) and the atrio-ventricular septal defect (AV canal); usually surgically correctable
- Bowel obstruction or constriction in around twelve percent of newborns; surgically correctable
- Hirschsprung's disease / Hirschsprung's disease in around twelve percent of newborns; surgically correctable
Most children have characteristic physical features of the syndrome after birth, so that the visual diagnosis often leads to a chromosome analysis being carried out to confirm the assumption. For this purpose, lymphocytes in the child's blood are examined for the presence of the additional chromosome material. If there are still doubts, the examination is carried out with material made from skin fibroblasts . While the diagnosis of translocation trisomy 21 is generally successful, it can, as already mentioned, happen that a mosaic trisomy 21 is diagnosed as a free trisomy 21. For the diagnosis of partial trisomy 21 is a locus - probe necessary.
Further symptoms and course
Trisomy 21 usually leads to a mental disability in humans , the degree of severity of which varies from person to person, but often belongs to the spectrum of a slight mental disability, especially in a competent environment (challenge and support). However, there can also be serious impairments in the sensory and / or physical area.
In many cases , impairments can be found in the sensory periphery: Around 57 out of 100 people with Down syndrome are hard of hearing . Often it is middle ear hearing loss or sensorineural hearing loss ; often caused by narrow ear canals or fluid build-up in the middle ear ( tympanic effusions ). The disturbances can be corrected by using hearing aids or ear tubes . 7 out of 10 have visual disturbances ( e.g. strabismus , nearsightedness / farsightedness , keratoconus (up to 15%) or lens opacities ). Changes in the cerebral cortex also suggest that the body's self-awareness and movement awareness are impaired, which often makes occupational therapy necessary.
Organ malformations and chronic disorders of body functions
Often people with trisomy 21 also show physical abnormalities: Chronic respiratory diseases are e.g. B. due to mostly narrower airways and a weaker immune system more common, as well as celiac disease and dysfunction of the thyroid gland (predominantly underactive). Approx. 40 to 60 percent are born with a congenital heart defect , with the atrial septal defect (ASD) and the atrio-ventricular septal defect (AVSD) being the most common.
Frequency and course of infectious diseases
Not only chronic, but also acute respiratory diseases occur more frequently in people with Down syndrome.
In connection with the COVID-19 pandemic, the "Institute for Marriage and Family", an institution of the Austrian Bishops' Conference , reassures concerned parents of children with Down syndrome: There are no "special risks for people with Down syndrome". There is only the risk that "the defense against infection and the immunological response to infections [...] could be somewhat weaker compared to the general population". As a result, children with Down syndrome can take longer to overcome an infection. In any case, the presence of Down syndrome, viewed in isolation, does not count as a “pre-existing condition”.
The Robert Koch Institute points out , however, that children with a congenital heart defect, immune deficiency, asthma or diabetes are generally classified as “previously ill” and assigned to the risk groups. Children with Down syndrome who have these previous illnesses are therefore considered "vulnerable" in Germany (ie they are exposed to an increased risk of a severe COVID-19 infection). In many countries in the Federal Republic of Germany, “vulnerable” pupils are not obliged to take part in face-to-face classes at their school during the COVID-19 pandemic.
In relation to the entire group (including adult) people with Down syndrome, a group of American researchers admits: “It is not clear whether Down syndrome itself increases the risk of a severe course [an infection with the SARS-CoV-2 virus ] known."
Susceptibility to cancer
Childhood leukemia is relatively common in people with trisomy 21 (see below).
Frequency of age (s) typical diseases
By the age of 40, almost all people with trisomy 21 develop diagnostic signs of Alzheimer's disease . On average, dementia becomes clinically conspicuous at the age of 55, although there is a wide range of fluctuations due to diagnostic difficulties. The amyloid precursor protein, which is held responsible for the development of the disease, is coded on chromosome 21, which presumably leads to the early and very frequent occurrence of Alzheimer's-like symptoms due to the increased expression .
In the past, many people with Down syndrome died as a result of organ malformations and dysfunction due to a lack of medical treatment options. Nowadays, however, in the vast majority of cases these can be treated successfully in the sense that most of the people affected by them can experience many years as adults in countries with effective healthcare systems.
The life expectancy of Europeans with Down syndrome has risen from an average of nine years (1929) to 60 years (2004), especially since organ malformations can now usually be treated very well. Every tenth person with Down syndrome now reaches the age of 70. The oldest known person with Down syndrome died in 2012 at the age of 83.
Usually, children with Down syndrome develop at about half the rate of development up to the age of five compared to regular children. The proceeds cognitive development (eg. As receptive language / comprehension) is usually faster than the motor (z. B. crawl, sit, run). This is usually followed by a reversal.
A strikingly large number of people with Down syndrome have special skills in the area of social behavior and emotionality , which can be observed even in early childhood. Studies have found that “many of these children show clear strengths in social functioning” and “more often have a lively mood, respond more to music and are less strenuous than other children of the same age”. Nevertheless, people with Down syndrome can be very different from one another in their social behavior and emotionality.
Most people with trisomy 21 have good receptive language (language comprehension). In the area of expressive language (speech expression), however, they usually show a clear developmental disorder in the phonological area as well as in the vocabulary and in the grammar . It can be improved to a considerable extent through speech therapy . Many children initially use the simple and easy-to-learn system of sign-assisted communication (GuK) to make themselves understood.
Language development and language impairment
The language skills of people with Down syndrome vary widely. However, there is no direct connection between the level of language proficiency and other skills.
Different forms of linguistic impairment represent a central problem. Initially, there is a noticeable delay in language development, but there are no deviations in the sequence of the above-mentioned language development stages.
Typical deviations can be observed in language acquisition, which are shown below:
- The early sucking-swallowing pattern persists in many children over the first six months
- mainly simple forward and backward movements of the tongue
- less canonical babbling , fewer variations in babbling, longer babbling sequences
- rare or severely delayed reactions to communication
- Difficulty using eye contact as a means of communication
- delayed object permanence
- first words are spoken relatively late
- Build up of vocabulary is greatly slowed down
- Speech comprehension corresponds to non-verbal cognitive skills
- take 80–100 words to form two-word sentences
- Two- and multi-word sentences are only formed between the ages of three and four
- Difficulties in acquiring grammar: Telegram style, no subordinate clauses
- the correct use of articles, prepositions, auxiliary verbs or tenses is often restricted
As with non-disabled children, the development of articulation and grammatical structures comes to an end around puberty. However, no age limits are accepted for language training.
Down syndrome is usually associated with moderate intellectual disabilities. But even in the case of severe intellectual disabilities, basic communication is possible through sensitive consideration of the individual phonetic and non-verbal forms of expression.
In mild and moderate forms of intellectual disability, linguistic development shows significant delays and qualitative deviations, such as a narrowing of the vocabulary, dysgrammatic forms and syntactic errors. There is a marked discrepancy between language comprehension (passive vocabulary) and language skills (active vocabulary). In addition, there can be various forms of articulation disorders, malformations of sounds and syllable omissions (although individual sounds can be correctly formed in isolation) and flow disorders. This leads to a limited intelligibility of the language. However, many children with Down syndrome develop relatively good to normal language and speaking skills.
Down syndrome can impair the function of the speech organs, for example through a rather slack and less mobile tongue. The open mouth position due to general muscle hypotonia (decrease in muscle tone), significantly more difficult nasal breathing and significantly reduced vital respiratory capacity lead to infections and colds more frequently. In addition, malformations of the teeth, jaw, palate, soft palate and tongue can have a considerable influence on the basic speech motor skills.
In the area of articulation, the syndrome-specific speech problems are diverse and multifactorial. Due to functional impairments of the speech organs, motor inadequacies caused by hypotonia and cognitive impairments, speech is often poorly understood. In the syntactic and pragmatic area, a narrowing of the vocabulary, dysgrammatic forms and syntactic errors can usually be found. Simple sentences can usually be formed correctly, subordinate clauses are less often formed.
Children with Down syndrome have a significantly higher risk of stuttering. In contrast to stuttering in people without trisomy 21, psychological components probably play no or only a minor role here. A trigger for the stuttering can often not be determined, but several causes can be assumed that work together unfavorably. Voice disorders are also common in people with Down syndrome: They usually have a rather hoarse-sounding and often indistinct voice.
Support of language acquisition
With the help of supported communication , alternative or additional forms of communication can be offered for understanding if the spoken language is restricted. The use of sign-supported communication (GuK) according to Etta Wilken has proven itself in children with Down syndrome .
Learning to read for children with Down syndrome is a particular help for language development and language acquisition, because the overriding goal is not to read itself, but to support learning to speak. For example, some children with Down syndrome have the ability to learn to read with relative success. Hence, they are also known as visual learners. They understand what they see better than what they hear. The initial concerns that these children could hardly master meaningful reading were refuted.
Learning to read takes place in small learning steps. It tries to avoid mistakes so that the children are not discouraged. Social reinforcement is also seen as very important. Before the children work with word cards, they first practice the differentiated visual differentiation and the desired learning behavior with normal picture lottos, i. H. Instructions such as “show” or “give” should be understood and followed. If the children then work with the word cards and do not immediately understand their meaning, games and exercises are carried out to teach them the meanings of the words. After the children have finally learned a basic vocabulary, there is a further systematic introduction to actual reading.
The entire learning process always takes a few years. The initial stages are usually done by the parents and the learning to read is usually completed at school age by the teacher. However, it is often impossible for families to conduct such a program at home. Therefore, learning to read in children with Down syndrome should rather be seen as a school task. However, it should also be borne in mind that certain experiences through spring are definitely important for school learning.
Holistic reading-learning methods are also particularly important for students with Down syndrome. For reading learners, reading should be associated with concrete meaning from the start. The additional use of phonetic signs (hand signals for letters) is particularly helpful for learning to read in children with Down syndrome. The additional visual and motorized representation supports reading and connecting letters and speaking at the same time.
Fertility and disease inheritance
Two thirds of all women with Down syndrome are fertile and can have children of their own. The probability that a woman with free trisomy 21 will father a child with Down syndrome with a healthy man is 50 percent. Children conceived in this way without a disability show more physical and cognitive abnormalities than babies born to mothers without additional chromosome 21.
Men with free trisomy 21 have long been considered sterile. Current studies indicate that the sperm are able to reproduce, albeit clearly slowed down. Parenting of men with Down syndrome has now been documented.
Trisomy 21 is usually not hereditary. Only with translocation trisomy 21 can a familial disposition be proven in around 30 percent of cases , namely when one or both parents are carriers of a so-called balanced translocation of a 21st chromosome :
Although the karyogram of the person concerned deviates from the usual in the number and structure of the chromosomes (45 instead of 46 individual chromosomes can be seen, one is longer than usual due to the translocation), the genetic information is balanced and there is no down- Syndrome on. The specialty of the balanced translocation of a 21st chromosome is that one of the two chromosomes 21 has changed its place and attached to another chromosome. This increases the likelihood that the unusually accumulated chromosome 21 will enter the new cell during cell division, which then has three instead of two chromosomes 21.
If one parent is a carrier of a balanced translocation in which a chromosome 21 is attached to one of the numbers 13, 14, 15 or 22, the probability is that the couple has a child with the respective translocation trisomy 21 (21/13 , 21/14, 21/15 or 21/22), theoretically at 25 percent. However, the actual frequency is lower, e.g. B. with the Robertson translocation 21/14 it is 1–15%.
In general, the range of tumors that occur in people with Down syndrome can be viewed as quite specific. While the incidence of carcinomas is reduced in adulthood, the risk of leukemia is above average, especially in childhood: acute megakaryoblastic leukemia ( acute myeloid leukemia , megakaryoblastic subtype / AMkL) is the form of leukemia that is most common in younger children with Down syndrome occurs. Your risk of developing leukemia is 20 times higher than the average, which means an occurrence rate of 1: 100. In contrast to regular children, however, children with additional genetic material on the 21st chromosome usually respond better to treatment with chemotherapy , their chances of recovery and survival are significantly higher and relapses are less common. One study found that a certain gene mutation, the so-called GATA1 mutation, more precisely the 40 kDa GATA1 protein , is responsible for this phenomenon . It causes an improved effectiveness of the medication. Therefore, it is probably precisely because of this mutation that children with trisomy 21 get this form of leukemia much more frequently, which, however, can also be treated more promisingly through this same mutation.
Aside from the increased risk of leukemia, people with Down syndrome are less likely to develop other forms of cancer. Six studies carried out independently of one another show that e.g. For example, neuroblastomas , nephroblastomas , abdominal cancer , stomach cancer , colon cancer and breast cancer are very rare: “Compared to age and gender, the chance for a person with Down syndrome to die from some form of tissue cancer is 50 to 100 times lower " as usual. The risk of developing breast cancer is in trisomy 21 z. B. around ten times less than in the average population. This below-average susceptibility to cancer is due to the inhibition of the supply of nutrients and oxygen to tumor cells. The DSCR1 gene encodes a protein that binds to the enzyme calcineurin . As a result, calcineurin does not come into contact with cells in the blood vessel walls as usual, so that these hardly form new blood vessels. The two genes DSCR1 and DYRK1A on chromosome 21 thus counteract pathological tissue growth.
The chance for someone with trisomy 21 to develop some form of epilepsy is about five to ten percent. This means that their susceptibility to epilepsy is up to ten times higher than the population average. In the group of people with intellectual disabilities, however, people with Down syndrome represent a group with a relatively low epilepsy rate.
Critical periods of life for the development of epilepsy in people with trisomy 21 are the first two years of life and the fourth and fifth decades of life: the West syndrome with onset in infancy and generalized tonic-clonic and myoclonic seizures in advanced adulthood as late epilepsy are the most common. Age-independent reflex epilepsy, triggered by a certain stimulus (e.g. flickering light, shock stimuli from unexpected touch, noises, etc.) is the third most common type of seizure in people with Down syndrome. Febrile seizures, on the other hand, are much less common in children with Down syndrome than in non-disabled children. The reasons for this are not yet known.
West syndrome , a special form of epilepsy, occurs in an average of one in every 100 children with Down syndrome . While this type is comparatively difficult to treat successfully in most children without the chromosome peculiarity on which Down syndrome is based, in children with trisomy 21 a significantly milder course and better responsiveness to medication can often be observed. EEG recordings often show more symmetry and less abnormality in them, and although not all children are seizure-free through medical treatment, children with Down syndrome following West syndrome are less likely to develop Lennox-Gastaut syndrome or other forms of epilepsy than Children without the triple set of the 21st chromosome.
Therapy methods that are often used in children with Down syndrome in order to optimally support the development of their skills are remedial education , occupational therapy , psychomotor skills , physiotherapy (often based on the methods of Bobath and / or Vojta ) and orofacial therapy according to Castillo Morales .
A low tension in the tongue muscles allows Down syndrome patients to stick their tongue out far. This makes it seem as if the tongue doesn't quite fit into the mouth. By training the tongue and face (partially supported by a so-called palate plate or stimulation plate ), the muscles can be strengthened to such an extent that the tongue remains inside the mouth as usual. Not every child with Down syndrome needs orofacial therapy and only a fraction of these children need a palatal plate.
For many people with Down syndrome, the use of animal-assisted therapy, e.g. B. in the form of pedagogical riding , proven to be beneficial.
Today there are many options for shaping life in adulthood in Western Europe for people with trisomy 21, such as: B. Shared apartments with individual assistance or workshops for people with disabilities . People with Down syndrome now also live in their own apartment in assisted living and are supported there according to their need for help. Children, adolescents and adults with trisomy 21 can benefit from various aids and suggestions in various areas ( language , motor skills , cultural techniques , etc.) and make their contribution to society. Many people with Down syndrome achieve considerable success, for example in the field of music , drama or painting or visual design , depending on their individual interests and the support and demands they receive . You have different hobbies, which, like other people, are based on individual interests. Many people with Down syndrome are also successful in the field of athletic performance. For example, in Germany since 2003 For example, at least one Down sports festival takes place every year, at which several hundred people with Down syndrome from the age of four can regularly compete in competitive sports .
School attendance and training
To this day, children with Down syndrome mostly attend school for the mentally handicapped. Schools with learning disabilities, other special needs schools and integration classes at mainstream schools can also accept students with Down syndrome. Most children today can learn to read and write with the necessary help and acquire at least a basic knowledge of arithmetic .
In some cases, people with trisomy 21 acquire regular school qualifications, and increasingly they are taking up regular jobs in the private sector. So far, only individual cases have become known worldwide in which they have been able to attend a university or even successfully complete it. The Spaniard Pablo Pineda and the Japanese Aya Iwamoto received media attention .
With the help of a tutor , Pablo Pineda attended a regular school, studied psycho-pedagogy in Málaga (graduated in 2004) and had previously obtained a diploma as a primary school teacher. He then worked for Málaga's social services as a consultant for families with a child with a disability and, since March 2009, at a school in Cordoba . Since 2010, Pineda has been giving lectures worldwide for the Fundacion Adecco , which is committed to the integration of disabled people. In autumn 2013 he hosted the program Piensa en positivo (German: think positive ) in the second program of Spanish television, La 2 .
Aya Iwamoto (* 1973) graduated from Kagoshima Women's University (today: Shigakukan University ) with a degree in English literature. Her achievement was recognized in the speech given by the president of the university to the graduating class: “That must give hope and encourage people with the same disabilities.” She works as a translator of children's books.
Down Syndrome in Public Life
The goal of complete social integration and unconditional acceptance, which is pursued by many clubs, associations, parents and, last but not least, by people with Down syndrome themselves , has not yet been achieved. A study by Lümkemann (2001) found that the majority of parents of a child with Down's syndrome (72 percent of the mothers surveyed, 100 percent of the fathers surveyed) are confronted with the question of why not prenatally after the birth Diagnostics would have taken. The development and consolidation of reservations of this kind within society make efforts to gain acceptance and integration of people with Down syndrome considerably more difficult . Many associations, foundations and parents try to counteract these tendencies through public relations work and information campaigns.
In particular, the commitment of people who are known to the general public as celebrities is regularly helpful. For example, Felicitas Woll (actress, among others "Lolle" in the television series Berlin, Berlin ), Christoph Schlingensief (among other things film and theater director), Ulrike Folkerts ( Tatort actress) got involved in the German Down Syndrome Weeks 2005 , Pia Wunderlich and Silke Rottenberg (players in the German women's national soccer team) as well as Irene Fischer and Joachim Hermann Luger ( Lindenstrasse actors) for people with trisomy 21 by taking part in a poster campaign by the DS Info Center. The posters were published in October 2005 and are intended to make it clear that a lot of things that appear different or strange about people with Down syndrome are basically completely normal and occur in everyone.
In 1974, ZDF broadcast the seven-part series Unser Walter , in which a person with Down syndrome grew up until he was 21 years old. The episode Born to Die (Original: For Love of Joshua ) of the Quincy series (1982) deals with the subject of Down syndrome and portrays both a foster family with six affected children ( Tyne Daly as foster mother) and one who died without surgery Child with Down syndrome, whose possible life prospects are discussed in detail.
Are you okay, Corky? (1989-1993) was the first series in which an actor with trisomy 21 took the lead role. It is now more common to see actors in television and cinema productions who have Down syndrome. In Germany in particular, Rolf "Bobby" Brederlow became known through various roles in television films and series , such as Bobby , Tatort and Liebe and other disasters . Brederlow supported the campaign You are Germany . In Austria, Christian Polster was the leading actor in three films by Niki List . Other well-known and successful productions in which people with Down syndrome play are the television series Lindenstrasse, Hospital der Geister and Kingdom Hospital as well as the feature films Mein Bruder, der Idiot , Florian - Liebe with all my heart and Schlafes Bruder .
Films in which people with Down syndrome, the main role play are, among other things, on the eighth day with Pascal Duquenne , The Girl in the Stone ( Israel , 1993) with a 16-year-old female teens , Me too - Who wants to be normal? , a Spanish love story from 2009, which is based on the life story of Pablo Pinedas , who plays the main role, Be my Baby with Carina Kühne and As you are by Wolfgang Murnberger (2011). In the United States, Lauren Potter gave the syndrome a popular face in the television series Glee over 56 episodes (2009-2015). The German feature film 24 Weeks , which premiered in 2016, focuses on the termination of pregnancy by fetocide after the prenatal diagnosis of Down's syndrome.
The March 21 was at the suggestion of de Erik Graaf, founder of the Dutch foundation Stichting Down Syndrome (SDS), by the European Down Syndrome Association (EDSA) for World Down Syndrome Day explained. The date was chosen because the 21st day is supposed to symbolize the 21st chromosome and March as the third month of the year can stand for the tripling of the chromosome material. It was implemented for the first time in 2006 with a wide range of action programs, and the day of action has been officially recognized by the United Nations since 2012 .
A high medical and educational standard and an improved knowledge of development opportunities for people with Down syndrome enable them in many countries to lead a relatively normal, healthy and long life that is increasingly well integrated into society. In certain regions this option does not yet exist or only partially.
There is little information and support for parents of children with Down syndrome in Bosnia-Herzegovina . Most children grow up without support, for example physiotherapy is only used in individual cases. Under the motto “Open your eyes!”, The founding ceremony of “Down Sy”, the country's first Down syndrome association, was held in September 2006 in the Olympic Stadium in Sarajevo. It was founded on the initiative of some parents of children with trisomy 21.
In 2003 there were 450 people with Down syndrome on the island of Malta . The children usually grow up bilingual (Maltese and English) and often live with their families into advanced adulthood. Elderly and elderly people mostly live in church or state-run homes, and in the elderly it is not uncommon for them to live in regular institutions. There is a Down Syndrome Center in Malta. It serves as a meeting place, and therapies and information events are offered there.
Norway has a large and varied range of assistance options. There are no special facilities; full integration into society exists for the most part. An oversupply of help and constant support from helpers can sometimes inhibit the development of independence , say critics.
The first self-help group for parents of children with Down syndrome was founded in Poland in 1995. Until then there was hardly any relevant literature in the Polish language.
In 2001 the first Down syndrome conference took place in Romania . Romanian literature with basic knowledge about trisomy 21 was published for the first time in 2002. However, Romania has made efforts to counter information deficits through contact with other countries. In the city of Băileşti , there has been a school especially for children with Down syndrome, the Centrul Teodora, for a few years .
In Russia , after the birth of a disabled child, including Down syndrome, parents are still advised to move the infant to a home. Inadequate human and material resources, malnutrition , unsanitary conditions, little freedom of movement and almost no educational attention, support and therapy, very few children with Down syndrome learn to walk and speak. Most of them die in childhood because they receive little or no medical treatment. Schooling is only provided for children and young people with minor disabilities, if at all, and job opportunities for adults with disabilities are only sporadic.
In 1997 , a parent group was founded in Slovenia within the association Sozitje , an association for people with intellectual disabilities, which until at least 2003 was the only Down syndrome self-help group in the country. With the support of EU funds, she has succeeded in ensuring that the members' children (around 120 in 2003) are offered early intervention for three years .
Spain is playing a pioneering role in integrating children with Down syndrome into school in Europe: in 2003, 85 percent of children were already attending a regular school and only 15 percent were given special schooling. However, the rate of those people with trisomy 21 who were integrated into regular working life after school was only three percent.
In 2012, the World Down Syndrome Congress in South Africa took place in Cape Town for the first time on the African continent . The state provides little information and support for parents of children with Down syndrome. There are insufficient training concepts. In the country there is the umbrella organization Down Syndrome South Africa (DSSA) with branches in almost all provinces. The National Down Syndrome Day will take place on 20 October every year. Schooling for children with Down syndrome in South Africa is still difficult and not mandatory. The desire to go to school for children with Down syndrome is not supported by the state and is often only possible after strong personal efforts and with private financial means. The themes of early intervention and inclusive schooling (Inclusive Education) are since 2010 intensively in the province of Western Cape propagated by a new association. The Down Syndrome Inclusive Education Foundation (DSIEF) is a non-governmental organization and founded the first project to school children with Down syndrome in regular kindergartens in the south of Cape Town in 2011. A satellite project was established in Paarl in January 2017 . These are the first and so far only projects in South Africa in which targeted early intervention is offered to children in mainstream schools with an Individual Education Plan (IEP). The learning concept used, called the Early Impact Program, is based on internationally established didactic concepts and learning techniques. It has been used in English-speaking integrative kindergartens and preschools since 2010. The DSIEF planning aims to create a corresponding primary school project in 2021.
In the United States , adoption agencies for children with Down syndrome, which a few years ago were considered difficult or impossible to find, now have long waiting lists. In addition, children with trisomy 21 often attend public mainstream schools and get university access at high school with individually tailored learning goals. In the United States, many people now see Down's syndrome as "a manageable difference and no longer an insurmountable problem" .
People's Republic of China
In the People's Republic of China , it is legally stipulated that live-born children with Down syndrome must be raised. The one-child rule did not apply until it was terminated in October 2015 following a medically confirmed diagnosis. Parents of a child with Down syndrome already had the right to have another child. With sporadic exceptions, children with trisomy 21 are left in hospital after birth and, if they survive, are given to homes. Parents who decide to raise their child themselves are usually confronted with resistance both within society and within the family. There is no early intervention , schooling is usually seen as secondary for children with disabilities, medical interventions often have to be fought hard and paid for in full, such as heart operations. The death rate in childhood is correspondingly high. The magazine Leben with Down's Syndrome speaks of conditions "similar to those in Europe fifty years ago".
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