Huntingtons

Question 1

Genetics Huntingtons - inheritance and what gene and protein affected

Answer 1

Autosomal dominant
CAG trinucleotide repeat mutation short arm chromosome 4 codes for glutamine

Question 2

WHat is anticipation

Answer 2

Younger age of onset with successive generations - increase in repeat CAG number increasing disease severity

Question 3

Number of repeats and how severe disease is

Answer 3

10-26 = normal
27-35 = asymptomatic or intermediate
36-39 = reduced penetrance
40+ full penetrance
50-60 = juvenile onset

Question 4

Pathophysiology of huntingtons

Answer 4

Mutation -> huntingtin protein clumping -> caudate and putamen degeneration
sults in degeneration of cholinergic and GABAergic neurons in the striatum of the basal ganglia

Question 5

Classic movements in huntingtons

Answer 5

Choreaform
Bradykinesia as disease progresses
Motor impersistence - cant sustain voluntary act
Milkmard grip - cant sustain grip

Question 6

Non motor symptoms of huntingtins

Answer 6

Cognition + personality changes
Difficulty w concentration, problem solving, irritability etc

Question 7

Managment of huntingtins

Answer 7

Tetrabenazine - chorea treat
Antipsychs for psych symptoms and chroea
MDT, furture plan etc

Question 8

How to drescribe a tremor

Answer 8

• Body distrubution
• Frequency
• Amplituse - how big
• Chronicity - How long, evolved
• Activation conditions - postural, kinetic
• Further neuro symptoms
• Genetic/drug induced clues - family history, worse with salbutamol

Question 9

Causes of chroea

Answer 9

Drug induced idiopathic parkinsonism
Basal ganglia stroke
Meningitis
Post infectious AI eg sydenhams post rheumatic fveer
Electrolyte imbalances
Genetic - huntingtons