DNA testing

Question 1

What causes Huntington’s Disease

Answer 1

CAG repeats over 40 in the coding region of the Huntingtin protein. This leads to spiny neuronal death in the striatum of the basal Ganglia. Is usually late onset and Autosomal dominant

Question 2

Symptoms of Huntington’s Diease

Answer 2

Loss of Movement, Cognitive disorders and Psychiatric and emotional disorders

Question 3

Cellular mechanisms of Neuron death

Answer 3

Huntingtin protein can be cleaved and become toxic. It can also aggregate and be toxic to the neurons. The cell will attempt to remove it via proteasomes yet will be clogged. leads to increased number of toxins now unable to removed by proteasome

Question 4

What is SCA

Answer 4

Is Spinocerebella Ataxia caused by repeats in the Ataxin protein. Autosomaml dominant and onset by 4th -5th generation. Pathology is the degeneration of the cerebellum, brainstem and spinocerebellar tracts

Question 5

What is Friedreich’s Ataxia

Answer 5

Is Autosomal recessive and is typically early onset (4th to 5th decade). Typical limb and gait ataxia and can be associated with Diabetes and cardiomyopathy.

Question 6

What repeats occur in Friedreich’s Ataxia

Answer 6

Is a GAA repeat in the Frataxin gene. Need over 60 repeats to induce disease. Frataxin deficiency leads to iron accumulation in the mitochondria and leads to ROS production.