Huntington's

Question 1

What is Huntington’s Disease?

Answer 1

An inherited neurodegenerative condition.

It is a progressive and incurable condition that typically results in death 20 years after the initial symptoms develop.

Question 2

Describe the genetics of Huntington’s Disease

Answer 2

• Defect in huntingtin gene on chr4
• Autosomal dominant
• Trinucleotide repeat > repeat expansion of CAG
• Anticipation may be seen (disease presents at an earlier age in successive generations)
• Results in degeneration of cholinergic and GABAergic neurons in the striatum of the basal ganglia

Question 3

What are the S/S of Huntington’s Disease?

Answer 3

• Movement – chorea, speech / swallowing, stumbling / clumsiness
• Cognitive – organising tasks, flexibility, impulse control, learning new information, difficulty concentrating, intellectual impairment
• Psychiatric – depression, irritability/mood swings, suicide in 9% of cases, personality change e.g. apathy and dystonia
• Saccadic eye movements
• Lack of insight (they don’t care that anything is wrong – tends to indicate an organic pathology)

Chorea = involuntary jerking or fidgety movements that tend to flow from one area to another

Question 4

What are the investigations for Huntington’s Disease?

Answer 4

• Genetic analysis (HTT gene)
• MMSE may be normal