Paper I once did for "health" class...
Down Syndrome occurs in
approximately one out of every 800 births. It is a
chromosomal disorder and a form of
mental retardation which causes mild to severe
learning disabilities. Over 350,000 in the
United States have Down syndrome.
Symptoms Of Down Syndrome
Causes
Down syndrome is a
genetic error that comes from a process called nondisjuntion. In
nondisjunction, paired
chromosome members fail to separate from each other during
meiosis; the cell division that reduces the number of chromosomes in
reproductive cells.
More specifically, Down syndrome occurs when an individual inherits all or part of an extra copy of chromosome 21. The most common cause for this is the disorder Trisomy 21, which accounts for some 95% of all cases. When a person has Trisomy 21, there is a third copy of chromosome 21 in every cell of the body.
The occurrence or Trisomy 21 is directly related to the age of the mother. The older a woman is when she gives birth, the more likely the child is to be to get Trisomy 21. Here is a chart of the likelihood of the child to have Trisomy 21 according to the mother’s age.
Chance of getting Trisomy 21-
If mother is 18 years old: 1 in 2100
If mother is 30 years old: 1 in 1000
If mother is 40 years old: 1 in 110
If mother is 45 years old: 1 in 35
Mosaic down syndrome is another type of chromosomal abnormality. This occurs when there is an extra copy of chromosome in only some cells in the body.
Another cause is Translocation. Translocation happens when a child inherits an extra, small piece of chromosome 21 which is attached to another chromosome. The child may inherit Down syndrome and not show any symptoms of it if there is only one normal 21st chromosome in addition to translocation. If there are two normal 21st chromosomes, the person will have only some features of Down syndrome.
Both Mosaic Down syndrome and Translocation account for only 2 to 3 percent of all cases.
Even though there is no cure for Down syndrome, it can be
detected early on.
Doctors can now use
prenatal tests to identify
fetuses with Down syndrome. First the mother has blood tests taken. The doctors scan for three different chemical levels in the blood, which helps determine the risk of Down syndrome in the
unborn child. If they find that the
risk for Down syndrome is high, they administer an
amniocentesis, a process where amniotic liquid surrounding the fetus is drawn from the mother’s body.
Fetal cells are in the liquid and can be checked for Down syndrome. They do this to double check their findings.
Other Health Problems Or Medical Conditions Caused By Down Syndrome
People with Down syndrome are also much more likely to have many more
medical conditions than people with out it. Heart
abnormalities that require
surgery occur in about half of all people with Down syndrome. The syndrome also causes thyroid problems in 10 to 20 percent of of the people it affects. This is why Down syndrome may
sometimes be linked to
dwarfism. People with Down syndrome are also some what more subject to acute
leukemia, although it is usually easily, successfully treated.
Since Alzheimer's disease occurs on a gene involved with Down syndrome, geneticists believe that there may be a link between the two. In early detected Alzheimer’s cases, doctors discovered a genetic mutation which is linked to the production of amyloid, a protein in plaques. Amyloid is sometimes linked to the destruction of neurons in the body. As people with Down syndrome grow older, they usually begin to form tangles and plaque in their brain, which is thought to cause some of Down syndrome’s symptoms. About 25% of all adults with Down syndrome will develop Alzheimer’s, as opposed to only 6% in people with out Down syndrome.
People with Down syndrome are also very vulnerable to getting assorted vision and respiratory problems, as well.
Survival Rate
As new methods of early detection and modern medicines are
discovered, doctors are finding better ways to treat Down syndrome patients more quickly and
effectively. The survival rate for people with down syndrome has increased tremendously since the
1970s. The
life expectancy of people with Down syndrome is slowly becoming more like that of people with out Down syndrome. Today in the United
States, 44% of all
people with Down syndrome
live to at least 60 years old. Over all, the
average life span for a person with Down syndrome is 55
years old.
Down Syndrome Life Styles and Conclusion
Children with Down syndrome can be taken care of in one of two ways. If they have
severe mental retardation, they can be sent to an
institution or a
foster home where doctors and people more
experienced with raising
handicapped children may take care of the child. The other option is for the child to stay at home, this is usually the case for a child with a
lesser retardation.
Children with Down syndrome can be trained the basic skills of life (walking, sitting, talking, playing), but usually after a child with out Down syndrome would. There is scientific evidence that children with Down syndrome that stay at home usually turn out to have a higher potential to succeed and live a normal life than those raised in an institution. People who have Down syndrome are highly responsive to their physical and social environment. With the right medical care and motivation, they can go on to make friends, attend school, find work, and make positive contributions to society.