Huntington's

Question 1

What is the genetic disorder/pattern?

Answer 1

Autosomal dominant

Question 2

Every child of a parent w/ HD has a (%) chance

Answer 2

50/50

Question 3

What is the genetic abnormality?

Answer 3

CAG repeat sequence –> “Huntington” or “HTT” pattern

> 40 Tri-nucelotide repeats on end of HD gene, chromosome 4

Question 4

What is the typical age of onset?

Answer 4

32-38 yo

- Earlier onset generation to generation as CAG sequence elongates

Question 5

What are family hx clues?

Answer 5

• Early dementia

- Multiple suicides

Question 6

What are personality/behavior changes?

Answer 6

• Abrupt

- Behavior sx include: changes in affect, mood, depression, OCD, suicide, psychosis

Question 7

What abnormal movements develop?

Answer 7

• Figidiness
• Ballism*
• Chorea*
• PD features, (rigidity, tremor)

Question 8

What cognitive changes occur?

Answer 8

Behavioral disturbances:

• anhedonia, apathy
• short-term memory loss, dementia
• poor judgment, loss of insight
• thought fixation

Question 9

What is the definitive dx test?

Answer 9

Genetic testing!

Question 10

How else can you dx?

Answer 10

• Clinically

- MRI (caudate atrophy)

Question 11

What is the tx?

Answer 11

Supportive (no cure or delay of onset):

• For ballism, chorea –> Benzos
• For PD sx –> PD drug
• For depression –> SSRIs