Neurogenetics

Question 1

What form of inheritance does DMD follow?

Answer 1

X-linked recessive

- caused by mutations in the dystrophin gene

Question 2

Which muscle groups are first affected in DMD?

Answer 2

Pelvic and shoulder girdles

Question 3

What is the typical method of mutation in the dystrophin gene causing DMD?

Answer 3

70% large scale deletions

30% point mutations, small insertions and deletions

Question 4

DMD is caused by new mutations in what percentage of affected boys?

Answer 4

1/3 boys (33%)

Question 5

What form of inheritance does Huntington’s disease follow?

Answer 5

Autosomal dominant trait

- a progressive neurogenerative disorder

Question 6

What is the pathological changes behind Huntington’s disease?

Answer 6

Loss of neurons from the cerebral cortex due to atrophy, in particular from the caudate area of the basal ganglia

Question 7

Which gene is altered in Huntington’s and what does it normally code for?

Answer 7

CAG 20 and it codes for glutamine

Question 8

Which disease displays a genetic heterogeneity? (has different underlying pathologies)

Answer 8

Alzheimer’s dementia

Question 9

What are the three pathological changes that occur in Alzheimer’s disease?

Answer 9

1. Loss of cortical neurons
2. Neurofibrillary tangles (intracellular)
3. Senile plaques (extracellular)

Question 10

What are senile plaques?

Answer 10

Extra-cellular protein deposits containing amyloid beta protein

Question 11

Which allele predisposes to Alzheimer’s disease?

Answer 11

Allele e4
(e2 is associated with longevity)