friedrich's ataxia

Question 1

FA cause

Answer 1

• autosomal recessive
• trinucleuotide repeat of the FXN gene that makes frataxin

Question 2

frataxin purpose

Answer 2

• encodes mitochondrial protein for nervous system, pancreas, and heart)
• helps put together iron sulfate clusters (for electron transfer and ATP production)

Question 3

FA gene silencing steps

Answer 3

1. trinucleotide repeat of FXN gene
2. less frataxin made
3. less iron sulfate clusters
   
   • mitochondria can’t use iron
   • poor electron transfer, ATP production
     *4. less ATP (energy for cells)
     *5. more iron + O2 –> oxygen radical and oxidative damage

*cell death!!
- neurons die –> ataxia
- cardiomyocytes –> hypertrophic cardiomyopathy
- pancreatic beta cells –> diabetes mellitus

Question 4

FA childhood symptoms

Answer 4

• walking changes
• muscle weakness
• poor proprioception
• fatigue
• starts in legs, moves up with time

Question 5

FA adulthood symptoms

Answer 5

• wheelchair bound
• heart failure
• vision loss
• hearing loss

Question 6

FA treatment

Answer 6

• incurable
• symptomatic

Question 7

FA diagnosis

Answer 7

• genetic testing
• MRI (brain and spinal cord)
• ECG (heart wall thickness)

Question 8

UMN signs in FA

Answer 8

upgoing plantar signs from corticospinal tract

Question 9

foot abnormalities in FA

Answer 9

pes cavis (high arched foot)

Question 10

nerve conduction results in FA

Answer 10

• absent sensory nerves
• well preserved motor action potentials