The condition is particularly common in Down syndrome because of physical anomalies such as low muscle tone in the mouth and upper airway, narrow air passages, enlarged tonsils and adenoids, and a relatively large tongue. The American Academy of Orthopaedic Surgeons lists a number of issues affecting the muscles, bones, and joints of people with Down syndrome.
One of the most common is an upper neck abnormality called atlantoaxial instability AAI , in which vertebrae in the neck become misaligned. It doesn't always cause symptoms, but when it does it can lead to neurological symptoms such as clumsiness, difficulty walking or an abnormal gait e.
About half of all babies with Down syndrome are born with heart defects, reports the CDC. These can range from mild problems that are likely to correct themselves over time to serious defects that will require medication or surgeries. The most common heart defect seen in infants with Down syndrome is an atrioventricular septal defect AVSD —holes in the heart that interfere with the normal flow of blood. An AVSD may need to be surgically treated.
Children with Down syndrome who aren't born with heart problems will not develop them later in life. People with Down syndrome tend to be at an increased risk for a variety of GI problems. One of these, a condition called duodenal atresia , is a deformity of the small tube-like structure the duodenum that allows digested material from the stomach to pass into the small bowel.
In a newborn, this condition causes a swollen upper abdomen, excessive vomiting, and lack of urination and bowel movements after the first few meconium stools. Duodenal atresia can be successfully treated with surgery soon after birth. Another gastrointestinal condition of note in Down syndrome is Hirschsprung disease —an absence of nerves in the colon, which can cause constipation. Celiac disease, in which intestinal problems develop when someone eats gluten, a protein found in wheat, barley, and rye, is more common in people with Down syndrome as well.
In this condition, the thyroid gland makes little or no thyroid hormone, which regulates bodily functions such as temperature and energy. Hypothyroidism can be present at birth or develop later in life, so regular testing for the condition should be done beginning when a baby with Down syndrome is born.
Hypothyroidism can be managed by taking thyroid hormone by mouth. According to the NIH, this seizure disorder is most likely to occur during the first two years of the life of a person with Down syndrome or to develop after the third decade. About half of the people with Down syndrome develop epilepsy after age It's also vital to understand that, despite what may appear to be innately unshakeable cheeriness, higher rates of anxiety disorders, depression, and obsessive-compulsive disorder have all been reported in Down syndrome.
These psychological problems can be successfully treated with behavior modification, counseling, and sometimes medication. They have an extra chromosome or part of an extra chromosome. Researchers believe that this extra genetic material affects growth of the maxilla part of the skull and the bone, cartilage, and connective tissue in the head, known as the cranial neural crest.
It creates common Down syndrome features such as upturned, almond-shaped eyes and a smaller head. The tongue is unusually large in many people with Down syndrome. In this condition, called macroglossia, the tongue is too big for the mouth so it protrudes out. Since babies born with Down syndrome also have impaired muscle control and the tongue is a muscle , the condition may be especially noticeable and problematic.
Overall, the vast majority of people who have Down syndrome report being happy with life and liking who they are. Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life. Centers for Disease Control and Prevention. Facts about Down Syndrome. Down Syndrome Education International. About us. Children's Hospital of Philadelphia. Data and Statistics on Down Syndrome.
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You will be subject to the destination website's privacy policy when you follow the link. Translocation carriers can have children who are carriers, children whose chromosomes show no rearrangement at all, or children with Down's syndrome. For translocations involving chromosomes 21 and any other chromosome, the chance of another child with Down's syndrome being born is about one in six if the mother is the carrier and about one in twenty if the father is the carrier.
A few people are carriers for a translocation between two chromosomes 21; in these people, who are quite ordinary themselves, the only possible outcome is a child with Down's syndrome. How can we know which type of Down's syndrome a baby has? There are no differences in the features or ability levels of people with regular trisomy 21 and translocation Down's syndrome.
The only way of knowing what type of Down's syndrome a person has, is by taking a blood sample and looking at the chromosomes. A very few children with translocation have partial trisomy 21 - where only a part of chromosome 21 is present in 3 copies. These children may have fewer characteristics of Down's syndrome.
Like the more usual type of translocation described above, this type may arise de novo, or a parent may carry it. As one third of people with translocation Down's syndrome have inherited the condition, their parents have a high chance of having another affected child and may wish to know whether this is so. To identify these parents, chromosome tests are done on all new babies with Down's syndrome. Blood samples can then be taken from parents of babies with translocations, to find out whether one of the parents carries the translocation.
Translocation carriers and other members of the family? Even if parents do not intend to have more children, knowing that one of them is a carrier can be important for all their children or other relatives. Relatives of a person who carries a translocation have an increased chance of being translocation carriers.
Mosaicism People with mosaic Down's syndrome have an extra chromosome 21 in only some of their cells. They therefore have a mixture of trisomic cells and ordinary cells. Depending on the proportion of trisomic cells, and which parts of the body contain these cells, individuals may be less affected both in their physical features and in their ability level than those with regular trisomy or translocation.
As for all types of Down's syndrome, it is not possible to say at birth how affected a person will be, only time will tell as the child develops. How does mosaic Down's syndrome happen? Mosaicism arises after the egg and sperm have fused at conception. As the cells divide and multiply by ordinary cell division, a chromosome goes astray and a single cell with an extra chromosome 21 is formed. This cell continues to divide by ordinary cell division together with the non-trisomic cells and a mixture is produced.
As with the other two types of Down's syndrome apart from when a parent is a carrier there is no known reason why mosaic Down's syndrome occurs. It happens equally often in parents of all ages. What are the chances of having another child with mosaic Down's syndrome? Mosaic Down's syndrome is very rare, therefore there are no accurate figures on this. It is believed that the chance is lower than it would be if the child had regular trisomy Some questions we have been asked Can a test-tube baby have the condition?
Yes - full chromosome tests are not carried out before the embryo is implanted. Is trisomy 21 the only kind of trisomy? Chromosomes 13 and 18 are larger than chromosome 21 and so the genetic imbalance is greater and the effects on the baby are generally more severe than in trisomy Trisomy for the X chromosome or an extra copy of the Y can occur, with relatively few effects for the child.
Trisomies of every other chromosome can occur, but usually those pregnancies end in miscarriage. Parents who have had a baby with one kind of trisomy are not thought to be more likely to have a baby with any other kind of trisomy. Is trisomy much more frequent in miscarriages?
Much more. In about half of all miscarriages occuring in the first 3 months of pregnancy, the developing baby has an altered number of chromosomes. Will gene therapy make a difference? As we understand more about how the genes on chromosome 21 interact to cause Down's syndrome, we can imagine a situation in which it might eventually become possible to switch off some of the genes or maybe even the whole extra chromosome responsible for Down's syndrome.
A great deal more understanding of the basic mechanisms of Down's syndrome and a great deal more development in gene therapy is needed before we can contemplate such treatment, but it remains a long-term possibility.
Are there any differences in the genes or chromosomes of grandparents of children with Down's syndrome? Unless the grandparent is a carrier of a balanced translocation a very rare event there are no known differences in the genes or chromosomes of grandparents of children with Down's syndrome from those of anyone else's grandparents.
There is nothing known that the grandparents might have done which would explain their grandchild being born with Down's syndrome. Can adults with Down's syndrome have children; and if so, what is the chance of their children having the condition?
A woman with Down's syndrome can have children. There have been only a few reports of men with Down's syndrome fathering children. If both partners have Down's syndrome there is a high chance of their children having the condition. As these events are still rare it is difficult to obtain accurate figures. My grandmother's sister had Down's syndrome. She died 40 years ago when she was Does this mean that I could have an increased chance of having a baby with the condition?
It is unlikely. There is a small chance that she would have had the inherited form of translocation Down's syndrome, in which case you could be a carrier. Chromosome testing was not introduced until so the family may not know what kind of Down's syndrome she had.
If your grandmother had a lot of children and grandchildren and none of them was affected, it is very unlikely that she was a carrier. However, it is important to note, there have been a handful of documented instances see American Society of Reproductive Medicine and Journal of Medical Genetics of men with Down syndrome who have fathered children. Reality : An increasing number of adults with Down syndrome in the U.
A small percentage are able to live entirely independently. In the U. More opportunities are available for education and employment today than ever before. Anecdotally, we know that people with Down syndrome can be excellent employees and some employers have reported a higher satisfaction level among ALL workers when they have co-workers who have Down syndrome.
Reality : People with Down syndrome are more like typical people than they are different. Everyone has feelings and moods. One recent literature review of previous studies found that people with Down syndrome are at a higher risk for depression.
And there is evidence that it is under-treated. Just as in the typical population, it is important that adults with Down syndrome have educational, work and social opportunities, as well as adaptive life-skills. Reality : As any related parent or professional will attest, people with Down syndrome absolutely have memory, and like typical individuals, their ability to remember varies from person to person.
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