Friedreich ataxia

Friedreich ataxia is an autosomal recessive disorder and is the most common inherited ataxia.  The dorsal root ganglia, dorsal columns, corticospinal tracts and heart are predominantly affected.

Epidemiology

• Incidence: 1/30 000-1/50 000
• Gender: Male = Female

Clinical Presentation

• A slowly progressive ataxia
• Mean age of onset 10-15 years
• May present in adulthood with milder disease

Physical Signs

• Dysarthria
• Spasticity in lower limbs
• Muscle weakness
• Absent/ reduced lower limb reflexes with extensor plantars
• Reduction/ loss of vibration sense and proprioception (dorsal columns)
• Progressive gait and limb ataxia
• Pes cavus
• Scoliosis
• Optic nerve atrophy
• Evidence of cardiomyopathy

Complications

• Average age of death is <40 years, most commonly due to cardiomyopathy.
• Diabetes mellitus (30%)