Huntington's Disease

2. It is a neurodegenerative genetic
disorder.
 affects muscle coordination and leads
to cognitive decline and psychiatric
problems.
 Chorea- abnormal involuntary writhing
movements
 Huntington’s Disease is also called
“Huntington’s Chorea”


3. Huntington's disease has been
recognized as a disorder since
at least the Middle Ages
 The first thorough description
of the disease was by George
Huntington in 1872.


4. 
Expansion of a CAG triplet repeat stretch within
the Huntingtin gene results in a different (mutant)
form of the protein, which gradually damages cells
in the brain, through mechanisms that are not fully
understood.

5. HD results from genetically
programmed degeneration of nerve
cells, called neurons,* in certain
areas of the brain.
 Specifically affected are cells of the
basal ganglia, structures deep
within the brain that have many
important functions, including
coordinating movement.


6. Within the basal ganglia, HD especially targets
neurons of the striatum, particularly those in the
caudate nuclei and the pallidum.
 Also affected is the brain's outer surface, or
cortex, which controls thought, perception, and
memory.


7. passed from parent to child through a mutation or
misspelling in the normal gene.
 The gene that produces HD lies on chromosome
4, one of the 22 non-sex-linked, or "autosomal,"
pairs of chromosomes.
 small sequence of DNA on chromosome 4 in
which several base pairs are repeated many,
many times


8. In people with HD, the sequence abnormally
repeats itself dozens of times ( three DNA bases).
 cause a new genetic mutation-an alteration in the
gene (occurs during sperm development).


9. Autosomal dominant disorder - only one copy of the
defective gene, inherited from one parent, is
necessary to produce the disease.

10. Early signs of the disease:
 mood swings or uncharacteristically irritable,
apathetic, passive, depressed, or angry.
 hostile outbursts or deep bouts of depression.
 having trouble driving, learning new things,
remembering a fact, answering a question, or
making a decision.

11. As disease progresses:
• uncontrolled movements in the fingers,
feet, face, or trunk.
• mild clumsiness or problems with
balance
• stumble or appear uncoordinated
• speech is slurred
• vital functions, such as swallowing,
eating, speaking, and especially walking,
continue to decline.
• Some individuals cannot recognize other
family members.

12. 
The most common causes of death are infection
(most often pneumonia), injuries related to a fall,
or other complications.

13. Take the family history or genealogy
 Using a blood sample
 Undergo a brain imaging test.
 Computed tomography (CT) and magnetic
resonance imaging (MRI)


15. Tetrabenazine- to treat the chorea
 Haloperidol- antipsychotic drugs
 Clonazepam- alleviate choreic movements,
control hallucinations and delusions.
 fluoxetine sertraline, nortriptyline – for depression
 Tranquilizers- help control anxiety
 Lithium- for pathological excitements and severe
mood swings


16. The worldwide prevalence of HD is 5–10 cases
per 100,000 persons, but varies greatly
geographically as a result of ethnicity, local
migration and past immigration patterns.
 Prevalence is similar for men and women.
 The rate of occurrence is highest in peoples of
Western European descent, averaging around 7
per 100,000 people, and is lower in the rest of the
world, e.g. one per million people of Asian and
African descent.


17. 
A 2013 epidemiological study of the prevalence of
Huntington's Disease in the UK between 1990 and
2010 found that the average prevalence for the
UK was 12.3 per 100,000.