Synopsis
Recognise Friedreich ataxia and other inherited ataxia patterns, choose genomic tests that detect repeat expansions, and coordinate syndrome-specific cardiac, endocrine, neurological and family care.
- Friedreich ataxia is usually autosomal recessive and caused by biallelic GAA repeat expansions in FXN, reducing frataxin and impairing mitochondrial iron–sulfur biology.
- Typical disease begins in childhood or adolescence with progressive gait and limb ataxia, dysarthria, impaired vibration and joint position, absent lower-limb reflexes and extensor plantar responses.
- Look beyond neurology: hypertrophic or fibrotic cardiomyopathy, arrhythmia, scoliosis, pes cavus, diabetes, hearing impairment and optic neuropathy materially affect surveillance and prognosis.
- The combination of areflexia from peripheral neuropathy and upgoing plantar responses from corticospinal disease is a classic localisation clue in Friedreich ataxia.
- Autosomal dominant spinocerebellar ataxias often show vertical transmission and age-related anticipation, but de novo disease, reduced penetrance and small families can obscure the pedigree.
- RFC1 biallelic repeat expansion commonly underlies late-onset sensory ataxia, bilateral vestibular areflexia and chronic cough, sometimes grouped as CANVAS.
- Routine exome or panel sequencing may miss repeat expansions, mitochondrial variants and structural changes; select the assay through an NHS genomic laboratory and ataxia specialist.
- No single rehabilitation or medicine plan fits every inherited ataxia: treat reversible mimics and syndrome complications, offer genetic counselling and review emerging disease-modifying eligibility through a specialist centre.
Key red flags
Syncope, exertional chest pain, palpitations or breathlessness in suspected Friedreich ataxia requires urgent cardiac assessment for cardiomyopathy or arrhythmia.
Rapid deterioration over weeks, constitutional symptoms or new encephalopathy is atypical for most hereditary ataxias and needs urgent acquired-cause investigation.
Dysphagia, recurrent aspiration, weak cough or weight loss requires prompt swallowing, nutrition and respiratory assessment.
A child with ataxia, recurrent infections and telangiectasia may have a radiosensitive DNA-repair disorder; involve specialist immunology and genetics before avoidable ionising exposure.
A variant of uncertain significance must not be used as a predictive diagnosis in relatives or as sole justification for irreversible treatment.
Investigation priorities
Confirm the common molecular cause of Friedreich ataxia and identify biallelic expanded alleles.
Management branches
A child or young adult has progressive gait ataxia with areflexia, sensory loss or skeletal features.
- Document onset, milestones, school and function, perform full cerebellar, sensory, reflex and plantar examination and construct a three-generation pedigree.
- Arrange specialist neurology and clinical genetics referral and request FXN repeat-expansion analysis through the NHS genomic pathway.
- Obtain baseline ECG, echocardiography, glucose assessment, hearing, vision, spine, foot, swallowing and mobility evaluation.
- Give a coordinated diagnosis discussion and rehabilitation plan, and offer carrier and reproductive counselling after molecular confirmation.