Down syndrome is a genetic condition caused by the presence of an extra chromosome 21. It occurs in three main forms: Trisomy 21 (95% of cases), where there are three copies of chromosome 21 instead of the typical two; mosaicism (1% of cases), where some but not all cells have an extra chromosome 21; and translocation (4% of cases), where part of chromosome 21 breaks off and attaches to another chromosome. The extra genetic material from chromosome 21 causes issues with brain and body development that result in both physical and mental symptoms that can range from mild to severe. While there is no cure, treatment focuses on managing symptoms through education, therapy, and surgery if needed to address health issues.

1. DOWN SYNDROME

2. WHAT IS IT?
Down Syndrome is a genetic condition in which a person has
47 chromosomes instead of the usual 46. The extra
chromosome is that of chromosome 21, where 3 occur instead
of the normal two. This happening is most commonly referred
to as Trisomy 21.

3. MOSAICISM AND TRANSLOCATION
There are two other forms of down syndrome, outside of
Trisomy 21, mosaicism and translocation. Trisomy 21 is 95% of
the cases of down syndrom. Mosaicism is when nondisjunction
of chromosome 21 takes place. However, it only takes place in
some of the cells, not all, after fertilization. Mosaicism accounts
for 1% of down syndrome patients. Translocation is when part
of chromosome 21 breaks off and attaches to another
chromosome. Most of the time, the attached chromosome is
14. Although there are only 46 chromosomes in this case, the
extra 21 section causes the condition. Translocation is the cause
of the other 4% of down syndrome cases.

4. THERE’S AN EXTRA CHROMOSOME. SO, WHAT?
This extra chromosome can be very detrimental. The human
body is “programmed” to be made out of 46 chromosomes.
Each codes for something different and knows exactly where it
belongs. The extra 21 chromosome causes issues with brain and
thus body development. This causes the affected person to
work a little different than those whom have the normal 46.

5. SYMPTOMS
As for many other conditions you can have a slight to severe
case of down syndrome. There are many symptoms that can
come along with down syndrome; both physical and mental. As
always, they differ from person to person. Not every person
who has this extra chromosome shows all of the symptoms.

6. PHYSICAL
In children, there is a unique look that often shows that they
have down syndrome, this generally consists of smaller shaped
heads with a possible flat region in the back and also eyes that
are rounded at the inner edge rather than pointed. When born,
many have less of a muscle tone and may also have excess skin
at the nape of the neck. It is also common to have small ears,
small mouths and a flattened nose. Furthermore, growth is
generally slowed throughout their lives and most do not reach
full adult height.

7. MENTAL
Generally, internal detriments consist of slowed social and
mental development. These can range anywhere from impulsive
behavior to slowed learning. Many also have a short attention
span. Once aware of the fact that people with this condition
have limitations, they can also show anger and frustration.

8. HOW DO YOU KNOW?
Often times, a doctor can tell the parents if the child has the
condition at birth, simply by the aforementioned physical
appearance. However, there are tests that are also used to
determine that the condition exists. Blood tests are what
generally confirm the extra chromosome. After birth, an
echocardiogram is done to check for heart defects which are
common in down syndrome babies.

9. AFTER BIRTH
Throughout their life time, people with down syndrome have to
have to have many tests done to make sure their body is
functioning in a healthy manner. These tests consist of eye,
hearing and dental exams, just like a person without the
condition. Also, they have to undergo xray and thyroid exams to
make sure development (xray) and everything is working
properly.

10. WHAT ELSE?
Down syndrome can cause other health issues, as well.
Cataracts are very common, most people having to wear
glasses. Dementia can develop. Gastrointestinal issues may arise
(consisting of vomiting). There is often joint dislocation issues.
Sleep apnea and teeth occurring at later times are also two
issues. All of these can cause problems with functions that
people without the condition would consider normal.

11. TREATMENT
There really is no specific “treatment” for this condition.
Behavioral therapy may be required, especially for the possible
anger issues. Also, surgery is necessary if there are heart or
intestinal issues. If these are not taken care of with surgery, more
serious and possibly deadly issues could arise. Obesity is
common so daily or regular exercise is recommended, as is for
any other person. Over all, the largest treatment may be special
education where the child is taught in a slower and more
appropriate pace.

12. FACTS
-Most females with down syndrome are able to get pregnant
but are at a higher risk for sexual abuse.
-People with the condition can live just as long as those without
as long as they are kept healthy.
-People with down syndrome are more susceptible to certain
forms of leukemia.
-As women get older, they are at a higher risk of having children
with down syndrome.
-Amniocentisis is one way to test for down syndrome in an
unborn baby.

13. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001992
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