Down Syndrome (Trisomy 21)

By. Skylor Caruso

What causes the disorder?

Down Syndrome is the most common genetic disorder in the US. Down syndrome displays birth defects, intellectual disabilities, characteristic facial features.

What gene or chromosome is affected?

In normal reproduction the sperm and the egg undergo cell division, but during the split of there 46 chromosome. The 21st chromosome does not get split and stays in both egg and sperm not just one or the other, therefor if fertilized will produce a down syndrome child.

Prenatal Test

Parents who are carriers of the genetic trans-location fro Down syndrome have an increased risk depending on the type of trans-location, therefor prenatal screening and genetic counseling are important. The most common prenatal test is the ultrasound and blood testing, others include first trimester screen, quad marker screen, and triple screen.(Down)

Symptoms or physical apperance

The common signs that a person may have down syndrome is his or her's slow growth rate, upward slant to the eyes, short neck, poor muscle tone, excessive flexibility, and white spots in the iris of the eye.(Down)

What population is affected?

Most common is the US, but can be found generally all around the world

Candidates for the disorder

People that are carrier of the down syndrome trans-location or have this disease are prime candidates for having a child with the same disease.


You cannot inherit the disorder unless your mother or father had it, In most cases the offspring inherited the trans-location required to make two copies of trisomy 21 in cell division.

Medical assistance

A person with Down syndrome likely will receive care from a team of health professionals, including, but not limited to, physicians, special educators, speech therapists, occupational therapists, physical therapists, and social workers.(What are common treatments)

Assistance while growing older

Down Syndrome could restrict you in a lot of way, many people with down syndrome do not work and receive welfare and food stamps to live. People with this disease may also have a nurse or family member take care of he or she.

Long-term outlook

Many people with down syndrome cannot preform things that people without the disease can. It is sad to think that people with down syndrome are rarely fertile and rarely receive a education.


Many treatments for Down syndrome are not to try to suppress the syndrome, it is to help them preform like a person without the syndrome.


There is no way to prevent it. The best thing you can do it get tested for your chances and see and results and percentage of risk your offspring is at.

Chance of having a child with disorder

As the woman's egg ages, there is a higher risk of the chromosomes dividing incorrectly.

20=1 in 1,600

25=1 in 1,300

30=1 in 1,000

35=1 in 365

40=1 in 90

45=1 in 30

Children with disorder

Children with disorder often have to take special courses through high school to help the develop at their own pace.

Current research

"Recent scientific research insists that scientist have established that a naturally occurring X chromosome "off switch" can be rerouted to neutralize the extra chromosome responsible for trisomy 21, also known as down syndrome."(University of Massachusetts)

Newest treatment

"In the past few years a number of laboratories have uncovered critical drug targets within disabled chemical pathways int he brain that might be restored with medication , at least two clinical trials are currently studying the effects of such treatments on people with down syndrome."(Laidman)


Clark, Heather. "Down Syndrome (Trisomy 21)." - Online Medical Encyclopedia. N.p., n.d. Web. 30 Apr. 2015.

"Down Syndrome: Trisomy 21 - Causes, Symptoms and Risks." American Pregnancy Association. N.p., 25 Apr. 2012. Web. 30 Apr. 2015.

"What Are Common Treatments for Down Syndrome?" What Are Common Treatments for Down Syndrome? N.p., n.d. Web. 30 Apr. 2015.

University of Massachusetts Medical School. "Scientists show proof-of-principle for silencing extra chromosome responsible for Down syndrome." ScienceDaily. ScienceDaily, 17 July 2013.

Laidman, Jenni. "Scientists Show Proof-of-principle for Silencing Extra Chromosome Responsible for Down Syndrome." ScienceDaily. ScienceDaily, n.d. Web. 30 Apr. 2015.