Diagnostic tests can typically detect whether or not a baby will have Down syndrome, but they can be more risky for the mother and developing baby. Neither screening nor diagnostic tests can predict the full impact of Down syndrome on a baby; no one can predict this.
Extra fluid in this region could indicate a genetic problem. Rarely, screening tests can give an abnormal result even when there is nothing wrong with the baby. Sometimes, the test results are normal and yet they miss a problem that does exist. Diagnostic tests are usually performed after a positive screening test in order to confirm a Down syndrome diagnosis.
Types of diagnostic tests include:. Many people with Down syndrome have the common facial features and no other major birth defects. However, some people with Down syndrome might have one or more major birth defects or other medical problems.
Many people with Down syndrome have small hands and feet and a single crease across the palms of the hands. About half of all affected children are born with a heart defect. Digestive abnormalities, such as a blockage of the intestine, are less common. Individuals with Down syndrome have an increased risk of developing several medical conditions.
These include gastroesophageal reflux, which is a backflow of acidic stomach contents into the esophagus, and celiac disease , which is an intolerance of a wheat protein called gluten. About 15 percent of people with Down syndrome have an underactive thyroid gland hypothyroidism.
The thyroid gland is a butterfly-shaped organ in the lower neck that produces hormones. Individuals with Down syndrome also have an increased risk of hearing and vision problems.
Additionally, a small percentage of children with Down syndrome develop cancer of blood-forming cells leukemia. Delayed development and behavioral problems are often reported in children with Down syndrome. Affected individuals can have growth problems and their speech and language develop later and more slowly than in children without Down syndrome. Additionally, speech may be difficult to understand in individuals with Down syndrome.
A small percentage of people with Down syndrome are also diagnosed with developmental conditions called autism spectrum disorders, which affect communication and social interaction. People with Down syndrome often experience a gradual decline in thinking ability cognition as they age, usually starting around age Down syndrome is also associated with an increased risk of developing Alzheimer disease , a brain disorder that results in a gradual loss of memory, judgment, and ability to function.
Approximately half of adults with Down syndrome develop Alzheimer disease. Although Alzheimer disease is usually a disorder that occurs in older adults, people with Down syndrome commonly develop this condition earlier, in their fifties or sixties.
Down syndrome occurs in about 1 in newborns. About 5, babies with Down syndrome are born in the United States each year, and approximately , people in this country have the condition. Although women of any age can have a child with Down syndrome, the chance of having a child with this condition increases as a woman gets older. As the registry grows, families and researchers learn more about Down syndrome and identify similarities and differences in the symptoms and treatment of people with Down syndrome from around the world.
The information collected helps guide future research and treatment. In the remaining cases, the error occurs after fertilization, as the embryo grows. Complete trisomy In this case, an error during the formation of the egg or the sperm results in either one having an extra chromosome.
So after the egg and sperm unite, the resulting cells will also have three copies of chromosome The complete extra copy of chromosome 21 is in all of the person's cells—or a complete trisomy. You can also hear from people with Down's syndrome about what's important to them on YouTube.
Your chance of having a baby with Down's syndrome increases as you get older, but anyone can have a baby with Down's syndrome. Speak to a GP if you want to find out more. They may be able to refer you to a genetic counsellor.
0コメント