Download Ataxia Telangiectasia

ATAXIA
TELANGIECTASIA
PowerPoint by Grayson Averette
Honors Biology, Block 1
The Basics
◦ Ataxia Telangiectasia is a disorder that affects various body systems
such as the nervous system and immune system. It also greatly
impacts the brain. It is an inherited disorder that is often recognized
before the age of five. It causes difficulty with coordination and
movement. People with Ataxia Telangiectasia often have high
amounts of AFP protein in their blood vessels.
Causes of Ataxia Telangiectasia
 This disease is an autosomal recessive gene meaning both copies of the ATM gene in each cell have
mutations. This is unlike a autosomal dominant gene, which means there is one copy of a mutant gene and
one normal gene in each cell.
It is not considered a sex-linked gene because boys and girls are equally affected by this disease.
A nondisjunction is when chromosomes fail to separate correctly. This is not an issue in this disease but
Ataxia Telangiectasia does occur due to a mutation.
In order for the symptoms to be present and the disease to actually occur in the body of the individual, both
parents must provide a defective gene.
It is caused by a mutated ATM gene.
Chromosome 11 is affected by Ataxia Telangiectasia
ATM Gene
The ATM Gene is located on Chromosome 11
It helps in controlling cell division in DNA repair and provides instructions for making proteins
Mutations on the ATM Gene causes functions of the gene to stop. Abnormal cell death occurs including the
death of brain cells. Therefore coordination of various body parts is not very good.
Symptoms
Ataxia Telangiectasia is a disease that is known for causing problems with coordinating movements. It can also
include many of the following.
 Difficulty walking
Problems with balance
Hand coordination problems
Involuntary jerking movements
Muscle twitches
Disturbances in Nerve Function
Slurred Speech
Trouble moving eyes side to side
Enlarged blood vessels in eyes and skin
Decreasing mental development
Discoloration of skin exposed to sunlight
Premature greying of hair
Seizures
Severe Respiratory Infections (happen repetitively)
Sensitivity to radiation
Facts
 Ataxia Telangiectasia occurs in 1 in 40,000 to 100,000 people worldwide. Therefore, it is a disease that is not
extremely common.
This is a disease that is found equally in both boys and girls
It has not been found to be present more in any specific ethnicity.
Symptoms start in kids very young. Most symptoms are present before the age of five and mental
development slows or stops between the ages ten to twelve.
Testing for Ataxia Telangiectasia
Doctors will first perform a physical exam. If the patient has Ataxia Telangiectasia, they may notice smaller
than normal sized tonsils, lymph nodes, and spleen. They may also notice slowed or absent development and
odd skin coloring with texture changes. If they have any suspicion, they may do any of the following tests.
 Alpha fetoprotein
B and T cell screen
Genetic testing
Glucose tolerance test
Treatment
◦ There is NO specific treatment for Ataxia Telangiectasia. The only
treatments are treatments directed toward the symptoms. It all
depends on the symptoms to know what kind of treatments and
medications need to be used. Therefore there is no true cure for
Ataxia Telangiectasia.
◦ Life expectancy varies but early death is common due to all of the
symptoms. Most tend to live into their early adulthood.
Interesting Facts
People with Ataxia Telangiectasia have a weakened immune
system causing many to develop chronic lung infections and
a higher risk of cancer.
35% of people with Ataxia Telangiectasia develop cancer.
Citations
◦ Ghr.nlm.nig.gov/condition/ataxia-telangiectasia
◦ www.nlm.nih.gov/medineplus/ency/article/001394.htm
◦ Ghr.nlm.nih.gov/gene/ATM
◦ www.brainfacts.org/diseas-disorders/diseases-a-to-z-from-ninds/ataxia-telangiectasia