ConditionBrain & nerves
Autosomal Recessive Cerebellar Ataxia
Autosomal recessive cerebellar ataxias (ARCAs) are a group of inherited conditions that damage the cerebellum, the part of the brain that coordinates movement, and often the nerves and spinal cord. They cause slowly worsening unsteadiness, clumsy hands, slurred speech and abnormal eye movements, usually starting before age 20. A child must inherit a faulty gene from both parents. Friedreich ataxia is the most common type. A few forms, such as ataxia with vitamin E deficiency, are treatable, so genetic diagnosis matters.
Also called: Recessive cerebellar ataxia, ARCA, hereditary recessive ataxia, early-onset hereditary ataxia
At a glance
- What it is
- A group of inherited disorders causing progressive loss of coordination.
- Inheritance
- Autosomal recessive; parents are usually healthy carriers.
- Onset
- Usually childhood to early adulthood, sometimes later.
- Main types
- Friedreich ataxia, ataxia-telangiectasia, ataxia with oculomotor apraxia, ataxia with vitamin E deficiency, ARSACS, and others.
- Diagnosis
- Neurological exam, MRI, nerve tests, blood tests, genetic testing.
- Treatment
- Mostly supportive; omaveloxolone for Friedreich ataxia; vitamin E or other specific treatment for a few types.
When to get help
Call 911 or go to the ER
- Sudden unsteadiness, slurred speech or double vision in a child or adult: call 911 to rule out stroke or other acute causes
See a doctor within a day or two
- Ataxia that develops over days to weeks
- Chest pain, palpitations, breathlessness or fainting in someone with Friedreich ataxia (heart involvement)
- Choking or coughing with meals, or weight loss
Book a routine appointment
- A child or teenager with clumsiness or unsteadiness that is gradually getting worse
- Frequent falls, worsening handwriting or slurred speech in a young adult
- Family planning when a relative has a recessive ataxia
What "autosomal recessive cerebellar ataxia" means
- Autosomal recessive: the gene is on a non-sex chromosome, and two faulty copies are needed. Parents each carry one copy and are usually unaffected. Each child of two carriers has a 1 in 4 chance of being affected.
- Cerebellar: the cerebellum, at the back of the brain, is affected.
- Ataxia: lack of coordination of movement.
Recessive ataxias often involve the spinal cord and peripheral nerves as well. They contrast with dominantly inherited spinocerebellar ataxias, which usually start in adulthood and appear in every generation.
Symptoms
- unsteady, wide-based walking and frequent falls
- clumsy hands, poor handwriting and difficulty with fine tasks
- slurred, slow speech (dysarthria)
- abnormal eye movements, such as nystagmus or difficulty starting eye movements
- loss of reflexes and reduced vibration and position sense in the feet
- swallowing difficulty
- foot deformities (high arches) and scoliosis
- fatigue
Symptoms progress slowly over years. Many people eventually need walking aids or a wheelchair.
Main types
| Type | Gene | Distinctive features |
|---|---|---|
| Friedreich ataxia | FXN | Most common; onset usually 5 to 15; heart muscle disease, diabetes, scoliosis, absent reflexes |
| Ataxia-telangiectasia | ATM | Toddler onset; red eye vessels; infections; cancer risk |
| Ataxia with oculomotor apraxia types 1, 2 and 4 | APTX, SETX, PNKP | Difficulty moving the eyes; neuropathy; low albumin or high AFP |
| Ataxia with vitamin E deficiency | TTPA | Resembles Friedreich ataxia; treatable with vitamin E |
| ARSACS | SACS | Spasticity, neuropathy, retinal changes |
| Cerebrotendinous xanthomatosis | CYP27A1 | Cataracts, tendon lumps, diarrhea; treatable with chenodeoxycholic acid |
| Refsum disease | PHYH | Night blindness, neuropathy; managed with diet |
| Ataxia with coenzyme Q10 deficiency | Several | May improve with CoQ10 |
Diagnosis
A neurologist will take a detailed history, including family history and whether parents are related (which increases the chance of recessive conditions), and examine coordination, eye movements, reflexes, sensation and strength. Tests include:
- MRI of the brain and spinal cord: shows cerebellar or spinal cord shrinkage and excludes other causes.
- Nerve conduction studies: many recessive ataxias cause neuropathy.
- Blood tests: vitamin E, AFP, albumin, cholesterol, cholestanol, lipoproteins, and others that point to specific types.
- Heart tests: ECG and echocardiogram, important in Friedreich ataxia.
- Genetic testing: a targeted test for Friedreich ataxia (a repeat expansion) and gene panels or exome sequencing for other types.
Acquired causes of ataxia, such as alcohol, vitamin B12 deficiency, celiac disease, thyroid disease, medicines and cerebellar damage from stroke or MS, are also ruled out.
Treatment
Specific treatments
- Friedreich ataxia: omaveloxolone is approved for adults and adolescents aged 16 and older and can slow progression.
- Ataxia with vitamin E deficiency: high-dose vitamin E stops progression and may improve symptoms.
- Cerebrotendinous xanthomatosis: chenodeoxycholic acid.
- Refsum disease: dietary restriction of phytanic acid.
- Coenzyme Q10 deficiency: CoQ10 supplements.
Supportive care
- Physical therapy: balance and coordination training, which can slow functional decline.
- Occupational therapy: aids for daily tasks and home adaptations.
- Speech and swallowing therapy.
- Mobility aids: canes, walkers, wheelchairs.
- Management of complications: heart disease, diabetes, scoliosis surgery, foot care.
- Genetic counseling for families.
Outlook
Progression varies by type. Friedreich ataxia often leads to wheelchair use 10 to 20 years after onset, and heart disease affects life expectancy. Some forms progress very slowly. Early diagnosis is important because a few types can be treated before damage accumulates.
Frequently asked questions
What is autosomal recessive cerebellar ataxia?
It is a group of inherited conditions in which a child inherits a faulty gene from both parents, causing gradual damage to the cerebellum and nerves. The result is progressive unsteadiness, clumsiness and slurred speech, usually starting before age 20.
What is the most common recessive ataxia?
Friedreich ataxia is the most common autosomal recessive ataxia in people of European descent. It usually starts between ages 5 and 15, and often affects the heart and blood sugar as well as coordination.
Can recessive ataxia be treated?
Most types have no cure, but physical therapy and supportive care help. Some forms are treatable, including ataxia with vitamin E deficiency and cerebrotendinous xanthomatosis, and omaveloxolone can slow Friedreich ataxia.
If I carry a recessive ataxia gene, will I get ataxia?
Carriers with one faulty copy usually have no symptoms. If both partners carry a variant in the same gene, each child has a 1 in 4 chance of being affected. Genetic counseling can explain options.
Sources
This guide was written from current patient and clinical guidance, including:
- National Institute of Neurological Disorders and Stroke: Ataxias and cerebellar or spinocerebellar degeneration; Friedreich ataxia
- MedlinePlus Genetics: Friedreich ataxia; Ataxia with vitamin E deficiency
- National Ataxia Foundation: Types of ataxia
- Friedreich's Ataxia Research Alliance: About FA
- GeneReviews (NCBI): Hereditary ataxia overview