Transcript What is Huntington`s disease?

Gene Therapy in
Huntington’s Disease
Project was done by Rejan Chin & Sharisa Ford
What is Huntington’s
disease?
Huntington's disease is a progressive,
degenerative disease that causes certain nerve
cells in your brain to waste away. As a result,
uncontrolled movements, emotional disturbances
and mental deterioration can be experienced.
Signs and symptoms usually develop in middle
age. Younger people with Huntington's disease
often have a more severe case, and their
symptoms may progress more quickly. Rarely,
children may develop Huntington's disease.
Huntington's disease usually develops slowly, and
the severity of signs and symptoms is related to
the degree of nerve cell loss.
Symptoms of Huntington’s
• Personality changes, such as irritability, anger,
depression or a loss of interest
• Decreased cognitive abilities, such as difficulty making
decisions, learning new information, answering
questions and remembering important information
• Sudden jerky, involuntary movements (chorea)
throughout your body
• Severe problems with balance and coordination
• Jerky, rapid eye movements
• Hesitant, halting or slurred speech
• Dementia
• Young people who develop Huntington's disease may
have signs and symptoms that mimic Parkinson's
disease:
• Muscle rigidity
• Tremors
• Slow movements
How Huntington’s Affects the
Gene
• Huntington's disease is an inherited condition
caused by a single abnormal gene. the illness is
referred to as an autosomal dominant disorder
because only one copy of the defective gene,
inherited from either parent, is necessary to
produce the disease. If one parent has the single
faulty gene, the chance that an offspring will have
the defect is 50 percent.
• The Huntington gene, which makes the normal
Huntington protein, is an essential component to
healthy nerve cells, the mutant Huntington gene
makes a toxic mutant Huntington protein. Mutant
Huntington contains increased levels of the amino
acid glutamine, which is generated by a repetition of
the DNA triplet CAG.
What is Gene Therapy?
• Gene therapy is a therapy which
switch off genes instead of adding
new ones could slow down or prevent
the fatal brain disorder Huntington's
disease. The method, exploits a
mechanism called RNA interference .
• Researchers in the United States say tests on
mice have shown the treatment could be
effective in humans, according to a report in
New Scientist magazine. Instead of giving
patients drugs to treat or control the
symptoms of the disorder, doctors attempt to
correct the underlying problem by
introducing healthy copies of damaged or
missing genes into some of the patient's
cells.
• The treatment has shown little evidence
until recently that it works. It has been
shown to work in animals but there has
been only limited success in humans.
• The scientists are confident that even
where both genes are faulty they will be
able to silence both and insert a new
healthy gene.
• In addition, they have carried out tests on
a similar disease using human cells and
have found that the technique can help to
reduce expression of the defective protein.
• In the case of Huntington's this could help
to slow down the progress of the disease
and reduce symptoms.
• "If you reduce levels of the toxic protein
even modestly, we believe you'll have a
significant impact," said Dr Davidson.
In conclusion, gene therapy
has shown positive signs to be
successful in the future for
Huntington’s Disease but
extensive studies will be
needed before the technique
could be tried in live
patients.