Trisomy 21

Trisomy 21-Down Syndrome

While I was creating the karyotype chart I realized that the 21^st chromosome is a trisomy. What that means is that there is an extra chromosome instead of the usual two and that was caused by an error in cell division also known as nondisjunction.

In the 21^st Chromosome either the sperm or egg fails to separate (fig 1) which creates the extra chromosome and as the embryo grows in each cell it ends up having a trisomy 21. A fetus that has the extra 21^st chromosome is born with a disorder called Down syndrome.

Figure1: This is what it looks like for a trisomy 21 (nondisjunction) cell division.

One in 691 babies in the United States are born with Down syndrome making it the most common chromosomal disorder.  About 400,000 Americans have Down syndrome and about 6,000 babies a year are born with Down syndrome in the U.S. Down syndrome can occur in people all over the world, but it is most likely to increase a chance for an older pregnant woman to have a child with Down syndrome.(fig 2)  

Figure 2:A chart that is able to show us the likelihood of mother ages that could give birth to a baby with Down syndrome.

Down syndrome is very easy to spot in people. Ever since they are born are their facial appearance and weak muscle tone is what makes people with Down syndrome stand out from others. Usually children with this condition have a delayed development and behavior issues. Their language develops later on in their lives and their way of speech may be harder for people to understand. Their behaviors may be something like attention problems, obsessive behavior and they often know how to be stubborn or throw tantrums. For people with Down syndrome it could happen that they are diagnosed with autism which affects their social and communication interaction and even later on in their 50’s they may experience a disability in thinking and that could lead them to Alzheimer’s disease, which is a brain disorder causing memory loss.

Garret Holeve is a mixed martial artist fighter, but unlike everyone else he is one born with Down syndrome. Holeve’s coaches and supporters opened up to Bleacher Report and to share his little story. Holeve is very functional for someone with Down syndrome, even though his understanding and reading level may be at a level for an eight or nine year old. Considering, Garret has this syndrome, he was not allowed to compete in any fight before, but he started a plea asking the Florida Boxing Competition to allow him to play and they were able to get more than 100,000 supporters.  Even though It may have been hard for people seeing someone with this disorder being punched or driven into the mat, it was great to see them stepping up and showing to others that they could be just like anyone else. 

It was very interesting to find out that October is Down syndrome awareness month . The national association for Down syndrome is sharing ways to promote awareness for our communities. This October is the chance for everyone to step up, show and spread some awareness by doing the simplest things like, talking to your class about this disorder, donate books to your school library, and one that caught my eye most of all is I is to organize little events this October to talk about the gifts of people with Down syndrome. This month it is important to show to others that it doesn't matter if someone is a bit different by the way that they look or act, but that they are people trying to live their everyday lives just like everyone else.


Sources: 
http://bleacherreport.com/articles/2225369-missouri-sanctions-bout-between-fighters-with-down-syndrome-and-cerebral-palsy

http://ghr.nlm.nih.gov/condition/down-syndrome

http://www.ndss.org/Down-Syndrome/

http://www.wlos.com/news/features/top-stories/stories/october-down-syndrome-awareness-month-18042.shtml#.VDj9IfmSySo