Huntington's Disease


Description:
Huntington’s disease (also known as HD) is a brain disorder that affects thinking, talking, and moving. It destroys cells in the Basal Ganglia section of the brain, which controls movement, emotion, and cognitive ability. Patients with Huntington’s disease have large amounts of the CAG triplet sequence that is present in the DNA. Huntington’s Disease causes clumps of protein to accumulate in the brain, and those same proteins become toxic. HD causes emotional issues, and usually begins to take affect at the ages of 30 through 50. Death from HD is commonly from indirect complications, such as heart failure or choking, but can also be caused by suicide from depression.

Inheritance:
Huntington’s Disease is inherited in an autosomal-dominant pattern. This means that if one parent has HD, then there is a 50% chance that the children of that individual will have Huntington’s Disease. Every person who inherits Huntington’s Disease will eventually end up suffering from the disease. Huntington’s Disease is caused by a defect on chromosome number 4, but is passed down like any other trait.




Symptoms:
· Depression
· Forgetfulness
· Antisocial behavior
· Mood swings
· Restlessness and poor coordination
· Involuntary movements
· Speech problems (slurs, lisps, etc.)
· Difficulty balancing and walking
· Memory, concentration, and organization problems
· Eventual paralyzation




Daily Life:





Diagnosis:
Huntington’s Disease can be diagnosed before birth by testing the amniotic fluids that surround the unborn fetus. After birth, HD can be diagnosed by physical and psychological tests. Also, a genetic test can determine if an individual has the gene that causes Huntington’s Disease. The expansion of the CAG triplet sequence in DNA is used to tell is a person has HD as well. Even though these test can tell whether a person has HD or not, they cannot predict when the symptoms of Huntington’s Disease will start affecting that individual.




Treatment:
There is no cure for Huntington’s Disease, or any other genetic disease at this time. However, in the case of Huntington’s Disease, there is not even medication that can slow down the symptoms of the disease. There are only certain medications available, and they can only make the patient more comfortable in their last days. There is depression and anxiety medicine available that can help some symptoms, and there are other medications that help to control involuntary movements. Physical and speech therapy are also in use at this time to attempt to help people with Huntington’s Disease lead more normal lives.




Research:
Although Huntington’s Disease was discovered in 1872, there was virtually no research done on it until the 1960’s. The Huntington’s Disease gene was isolated in 1993, and was identified in chromosome #4. Today, there are a couple organizations that are dedicated to finding a cure to HD and funding research, such as the Huntington’s Disease Society of America. Modern methods of research are in use currently, like neurobiology, clinical research, imaging, animal models, and fetal tissue research. Even with all the research that is currently in progress, there is still a long way to go to find a cure for Huntington’s Disease.



Additional Facts:
1 in 30,000 people has Huntington’s Disease in America alone. That means that about 250,000 people are currently diagnosed with Huntington’s Disease. Huntington’s disease was named after George Huntington, who discovered the disease in 1872. HD is considered one of the more “common” genetic diseases, and it affect the Basal Ganglia section of the brain. Suicide is very common in HD patients because of the depression side effects. It is possible for children to get HD, but rarely do those children live into adulthood.





Punnett Square:


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Pedigree Chart:


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Pictures:
HDpatient1.jpgHDpatient2.jpgHDtherapy1.JPG



Resources:

Huntington’s Disease Society of America: www.hsda.org

Learn.Genetics Huntington’s Disease: http://learn.genetics.utah.edu/content/disorders/whataregd/hunt/

PubMed Huntington’s Disease: http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001775/