Friedreich ataxia is an autosomal recessive condition resulting from a mutation of a gene locus on chromosome 9 that affects the nervous system and causes movement disorders. The disease is linked to a gene called FXN. Normally this gene will cause your body to produce up to 33 copies of a specific DNA sequence. In people with Friedreich’s ataxia, this sequence may repeat 66 to over 1,000 times. When production of this DNA sequence spirals out of control, severe damage to the brain’s cerebellum and the spinal cord can result. It's also called spinocerebellar disease. 

The hallmark clinical features of Friedreich ataxia are;

1. Onset between 5 and 15 years of age

2. Progressive ataxia of gait

3. Loss of joint position and vibration sense

4. Absent tendon reflexes in the legs

5. Poor coordination or Lack of coordination 

6. Muscle weakness

7. Extensor plantar responses

8. Foot deformities 

9. Pes Cavus

10. Scoliosis 

11. Dysarthria

12. Visual disturbances 

Approximately 75% of people with Friedreich’s ataxia have heart abnormalities. The most common type is hypertrophic cardiomyopathy, a thickening of the heart muscle, that may lead to heart failure or irregularities in heart rhythm (cardiac arrhythmias).

About one third of the people with Friedreich ataxia develop diabetes mellitus.