Disease Description (Causes and Symptoms)
- Definition summary: Friedreich ataxia is an autosomal recessive genetic disorder in which symptoms usually begin in childhood or adolescence (typically at 10–15 years of age) and progressively worsen, causing ataxia.
- Cause: The primary cause in most cases is a pathological increase in the number of GAA trinucleotide repeats located in intron 1 of the FXN (frataxin) gene. Rarely, point mutations may also be responsible. Frataxin deficiency causes impaired function of mitochondrial iron–sulfur proteins and oxidative damage.
- Pathophysiology (brief): Decreased frataxin → mitochondrial dysfunction → degenerative changes in the nervous system (especially the dorsal roots, posterior columns, spinocerebellar tracts, and corticospinal tracts) and cardiac muscle → sensory/motor ataxia and cardiac complications.
- Main symptoms
- Early symptoms: Unsteady gait (ataxia), impaired balance
- Sensory loss: Loss of vibration and proprioception (position sense)
- Neurological examination: Severely diminished deep tendon reflexes (especially in the lower limbs), absent abdominal/cremasteric reflexes, positive Babinski sign
- Other: Slurred speech (dysarthria), ocular abnormalities such as nystagmus, pes cavus, scoliosis/kyphosis (kyphoscoliosis)
- Heart: Progressive cardiomyopathy (primarily hypertrophic), arrhythmias, T-wave inversion on electrocardiography, and others
- Typical course: Many patients become unable to walk within approximately 10 years after symptom onset, and survival beyond age 40 is relatively uncommon (with individual variation).
Treatment Methods
- Definitive treatment: There is currently no established definitive treatment (cure). Gene therapy and various drug therapies are under investigation.
- Standard and supportive treatment
- Rehabilitation: Physical therapy (maintaining balance and strength), occupational therapy (assistance with activities of daily living), speech therapy
- Assistive devices: Mobility aids such as orthoses, canes, and wheelchairs
- Orthopedic treatment: Surgery may be considered when correction of severe scoliosis or pes cavus is necessary
- Cardiac management: Regular cardiac monitoring (electrocardiography and echocardiography); drug treatment for arrhythmias or heart failure (such as beta blockers and ACE inhibitors); a pacemaker/defibrillator may be considered when necessary (if there is an arrhythmia risk)
- Endocrine management: Standard diabetes management when diabetes is present
- Medications and supplements (investigational and adjunctive use)
- Antioxidants such as coenzyme Q10 and vitamins have been studied in some research, but they are not established standard treatments
- Antioxidant drugs such as idebenone have been studied in the past, but the level of recommendation differs among clinical guidelines — consultation with the treating specialist is necessary
- Precautions (daily management)
- Fall prevention (adjusting the home environment and using assistive devices)
- Immediate evaluation if cardiac symptoms (chest pain, syncope, tachycardia, etc.) occur
- Anesthesia-related risks during infection or surgery (cardiac function evaluation is necessary)
- Regular checkups: Follow-up coordinated among neurology, cardiology, and endocrinology (diabetes) is recommended
Checklist Before an Outpatient Visit (Including Example Questions)
- Items to prepare
- List of currently taken medications and supplements (including dosage and administration times)
- Previous medical records (genetic test results, electrocardiography/echocardiography results, spinal imaging, orthopedic records, etc.)
- Notes summarizing when symptoms began and how they have progressed (initial symptoms, aggravating factors, frequency of falls, etc.)
- Family history (similar symptoms, genetic diseases, and test results of parents and siblings)
- Information to tell the doctor in advance during the visit
- Whether there has recently been syncope, ataxia, shortness of breath, chest pain, or persistent fatigue
- Changes in daily functioning (walking distance and whether assistive devices are needed)
- Example questions (to help patients/caregivers prepare to ask the doctor)
- “Could you review my genetic test results, if I have any?”
- “What cardiac tests should I have, such as electrocardiography or echocardiography?”
- “What are the effectiveness and safety of the supplement I am currently taking, such as CoQ10?”
Examples of General Questions to Ask the Doctor
- What are the expected effects and side effects of this medication (or supplement)?
- What can I expect regarding my prognosis (the rate of functional decline and how long I may be able to maintain my daily life)? What factors affect the prognosis?
- How often should I undergo cardiac tests?
- How should my exercise and physical therapy plan be structured?
- What procedures are involved in genetic counseling and recommending testing for family members?
Examples of Disease-Specific Questions
- What is my GAA repeat number (or what do my genetic test results show)? How is the number of repeats related to the prognosis (age at onset/rate of progression)?
- Based on my current electrocardiography/echocardiography results, what cardiac treatment or preventive measures do you recommend? If my arrhythmia risk is high, should I consider placement of a pacemaker or defibrillator?
(Note: Clinical and genetic diagnosis is important, and specific testing and treatment plans for individual patients vary according to the evaluation by the treating specialist.)