Huntingtons 3A

Question 1

What is Huntingtons?

Answer 1

Auto dom with full penetrance (all genotypes will express phenotypes) + anticipation
Lack of GABA + excessive nigrostriatal pathway

Question 2

Pathology>?

Answer 2

CAG repeats on chromosome 4 affecting HTT gene
Trinucleotide expansion repeats

Question 3

How many repeats mean you have Huntingtons?

Answer 3

<35 = no huntingtons
35-55 = huntingtons
60+ = severe huntingtons

Question 4

Sx of Huntington’s?

Answer 4

Chorea (excessive limb jerking)
Dementia
Psychiatric issues
depression!

Question 5

Dx of huntingtons?

Answer 5

Clinical; fHx of earlier + more severe Huntingtons
Genetic test if necessary (>35 CAG repeats)
MRI = Striatum atrophy (caudate, putamen, nucleus accumbens)

Question 6

Tx ?

Answer 6

Extensive counselling
DA antagonists for chorea (tetrabenazine - vesicular monoamine transporter 2 - i)
Depression = SSRI
Psychosis = antipsychotics

Question 7

The more trinucleotide repeats mean?

Answer 7

The more trinucleotide repeats, the earlier and more severe Sx present
ANTICIPATION

Question 8

What are the 1^ and 2^ causes of death in Huntingtons?

Answer 8

1 = resp arrest
2 = suicide