Lou Gehrig's Disease
Biology Genetic Disease Project
Introduction
I have decided to study Lou Gehrig's disease for this project. I chose to research this disease because I have heard of several people that have been diagnosed with this disease including Stephen Hawking. I have always wanted to learn more about what takes place during this ailment, but have never had the time or motivation to do so. I think that I will find this project interesting and fun to learn about, which is why I chose this disorder.
What is Lou Gehrig's Disease?
Lou Gehrig's disease is just another name for amyotrophic lateral sclerosis, or ALS. ALS effects the nerve cells located in the brain and spinal cord. Amyotrophic literally means "no muscle nourishment", lateral mean that the disease takes place in the spinal cord, and sclerosis comes from the fact that the affected area is scarred and hardens.
Symptoms
This neurodegenerative disease kills motor neurons and prohibits the brain from controlling muscle movement. Because patients lose control of their muscles, many are completely paralyzed in the last stages of this disease. Symptoms in the early stages of Lou Gehrig's Disease include muscle weakness in arms, legs, and muscles that aid in speech, swallowing, and breathing. Other symptoms include twitching, cramping, loss of arm or leg use, difficulty in speech, shortness of breath, and increased difficulty in breathing and swallowing.
Causes of Lou Gehrig's Disease
There are many possible causes of ALS including:
1) Gene Mutation - gene mutations can lead to a form of ALS that is inherited. This inherited form is very similar to the non-inherited form of this disease.
2) Chemical Imbalance - patients that suffer with Lou Gehrig's Disease tend to have higher levels of glutamate in their spinal fluid. Glutamate is a chemical that sends messages to the brain and too much of this chemical is often results in damaged or dead nerve cells.
3) Disorganized Immune Response - this is when a persons immune system attacks the nerve cells in his/her body, killing the cells.
4) Protein Mishandling - proteins within the cells may be misused and this leads to an increase in unusual forms of proteins in the cells, killing them.
1) Gene Mutation - gene mutations can lead to a form of ALS that is inherited. This inherited form is very similar to the non-inherited form of this disease.
2) Chemical Imbalance - patients that suffer with Lou Gehrig's Disease tend to have higher levels of glutamate in their spinal fluid. Glutamate is a chemical that sends messages to the brain and too much of this chemical is often results in damaged or dead nerve cells.
3) Disorganized Immune Response - this is when a persons immune system attacks the nerve cells in his/her body, killing the cells.
4) Protein Mishandling - proteins within the cells may be misused and this leads to an increase in unusual forms of proteins in the cells, killing them.
How is ALS inherited?
About 90-95% of ALS patients do not inherit this disorder. This disease is usually random. About 5-10% of diagnosed patients are affected by this disease because of gene mutations. Sometimes Lou Gehrig's Disease is caused an autosomal recessive pattern. This happens when both parents carry the mutated gene and then pass it to their offspring. Although rare, ALS is sometimes carried in an X dominant pattern. This happens when one of the mothers X chromosomes have mutated slightly or when the fathers X chromosome has mutated. Females with Lou Gehrig's disease tend to suffer less severe symptoms than males. Since this disease is caused by mutations, there are often many different results as there are a variety circumstances in each case.
How is ALS treated?
While there is no known cure for Lou Gehrig's disease at the moment, there are several different ways to treat the symptoms. The only medication that is approved by the FDA at this time is riluzole. This drug helps to combat glutamate to slow the progression rate of ALS. Doctors might also suggest medicines that help with individual symptoms of ALS such as muscle cramps, spasm, fatigue, and pain. Therapy can also help control different symptoms of ALS. Therapy given to patients includes breathing therapy, physical therapy, occupational therapy, speech therapy, nutritional support, and psychological and social support. Gene therapy is being experimented with certain ALS patients. The theory is that if damaged nerve cells can be corrected, the patient might have a higher chance of survival. However, not all cases of ALS are caused by the certain protein targeted by gene therapy; therefore, gene therapy is able to help very few ALS victims.
How is Lou Gehrig's Disease Diagnose?
There are may different tests that help to diagnose ALS. These include:
- Electrodiagnostic tests
- Blood and Urine tests
- Spinal tap
- X-rays
- Myelogram of cervical spine
- Muscle and nerve biopsy
- Neurological examination
Genetic counseling is an option for ALS, but it does not provide much help in diagnosing the disease because most people who have ALS did not inherit it. Genetic testing is only useful for the small percentage of people that have a strong family history of the disease.
Who is more likely to get ALS?
Who gets ALS?
- Most people are diagnosed between the ages of 40-70.
- 20% more likely to happen in men
- Military veterans have an increased chance of getting ALS.
- 93% of patients in the US are Caucasian
Punnett Square
Although ALS is often random and can occur in individuals that don't even carry the gene that is often found in ALS patients. However, this disease can also be inherited through a recessive gene. The punnett square below shows how this could take place.
Punnett Square
In this instance both the mother and the father are carrier's of the gene that can cause ALS. The chance that their child will be affected is 25%.
Pedigree
This pedigree shows the possible offspring of a male with ALS and a female without.
Graph showing causes of ALS
The majority of this chart represents the random causes of ALS. This graph states that 10-15% of ALS cases have a strong family history of Lou Gehrig's disease.
What did I learn?
I learned a lot about Lou Gehrig's disease during the completion of this project. I started out knowing only that this disease affected Stephen Hawking and that it was something nerve related. As I near the end of this project, I finish with a wealth of knowledge regarding this disease. I now know what causes this disease, what takes place in ALS, and what can be done to help the patient. Perhaps you've heard of the ALS ice bucket challenge. Perhaps, like me, you didn't know what ALS even was. (I thought it was American Sign Language, but then realized that was ASL, not ALS.) I hope that this presentation has helped you, the viewer, become better acquainted with this disease just as it has helped me.
Video
Watch the educational video below to better understand what takes place during this disease.
What is A.L.S. or Lou Gehrig's Disease ?
Video
This video tells the story of Mike, as he struggles with Lou Gehrig's Disease. Notice the rapid deterioration in speech and movement.
ALS - Lou Gehrig's disease
ALS nerve and muscle
This is what an ALS-affected nerve and muscle look like compared to a normal nerve and muscle. Notice how the nerve is shriveled and the muscle is significantly smaller.
Lou Gehrig
Lou Gehrig was a Yankee baseball player who was inducted into the baseball hall-of-fame. In the 1930s he was diagnosed with ALS.
Stephen Hawking
Stephen Hawking is one of the most well-know cases of Lou Gehrig's disease. He studied physics and cosmology at Oxford and Cambridge. At the age of 21, Stephen was diagnosed with ALS. He has said, "however difficult life may seem, there is always something you can do and succeed at."
Resources
http://www.alsa.org/about-als/what-is-als.html
http://www.alsa.org/about-als/symptoms.html
http://kidshealth.org/kid/grownup/conditions/als.html
http://www.hawking.org.uk/about-stephen.html
http://ghr.nlm.nih.gov/condition/amyotrophic-lateral-sclerosis
http://www.alsa.org/research/about-als-research/gene-therapy.html
http://www.alsa.org/about-als/diagnosing-als.html
http://web.alsa.org/site/PageServer?pagename=ALSA_Genetics_Testing
http://t3.gstatic.com/images?q=tbn:ANd9GcRJrZPqWUTVbFY8o-rG0JThhdqjpTJMnKrc_Amwz7Dpshb4y-Cs