What is Hereditary Ataxia?


The hereditary ataxias are a group of genetic disorders leading to slow, progressive degeneration of normal gait and poor hands, speech and eye coordination. In many cases, this condition is associated with atrophy of the cerebellum. Hereditary ataxias are caused by a defect in the gene which produces abnormal protein and destroys the functions of the nerve cells in the cerebellum and spinal cord. Hereditary ataxias occur 1 or 5 in every 100,000 persons.

Patterns of Inheritance


Hereditary ataxias are grouped according to the pattern of inheritance:

  • autosomal dominant pattern - inherited when one parent carries a copy of the defective gene
  • autosomal recessive parent - inherited when both parents carry a copy of the defective gene
  • x-linked pattern - inherited from the mother

Types of Ataxias


The first type of Ataxia was identified in 1993. It was an autosomal dominant type known as Spinocerebellar Ataxia Type 1 (SCA1). Other similar dominant type genes were found (SCA2 and SCA3). Currently there are 36 mutations of SCA from SCA1 to SCA36.

The common recessive ataxias are Friedrich’s Ataxia (FRDA), Oculomotor Apraxia Type 1 and Type 2 (AOA1 and AOA2).

Signs and Symptoms


Clinically varied signs and symptoms may occur among the different groups of ataxias. Some common symptoms include:

  • unsteady gait
  • poor hand, eye and speech coordination
  • slurring speech
  • trouble with fine motor tasks
  • trouble with swallowing

Diagnosis


If the neurologist suspects one of the hereditary ataxias, he/she will usually take a family history and history of the person’s symptoms along with a detailed neurological examination. Some of the tests that are used to diagnose hereditary ataxias include:

  • neuroimaging - a CT/MRI scan of the brain can enable detection of ataxia if it indicates a shrinkage of the cerebellum and other brain structures
  • spinal tap or lumbar puncture - this test enables collection of a sample of spinal fluid for analysis
  • genetic testing - to check for various genotypes of ataxia. Not all ataxias can be genetically tested

Please see list of specialized genetic testing centres

diagnosis
Genetic testing is available for many of the hereditary ataxias
Image Source: Pixabay

Treatment and Management


Currently, specific treatment is available for the ataxias. Treatment is aimed at preventing complications and enabling independent living. An interdisciplinary team of doctors including neurologists, orthopedicians and physiotherapists will be required to take care of the clinical needs of the child/adult. In the early stages when just diagnosed, it is important to immediately start physiotherapy and rehab to prevent further deterioration and maintain a certain level of mobility.

Physiotherapy is highly recommended to preserve muscle strength. Wheelchairs may be required in some cases. Adaptive devices are also useful to perform daily tasks. Some of the devices include specialized crutches and sticks, special utensils for eating and communication aids. Other helpful therapies include occupational therapy and speech therapy.

Living with Ataxia


Children and adults with Ataxia must be encouraged to participate in all life activities and must be encouraged to go to regular schools, colleges and participate in social activities. Genetic counselling and psychosocial counselling must be made available whenever required with other supportive measures.

Look up our list of patient organizations in India for help and support

Living with MPS
Children must be encouraged to engage in physical activities
Image source: Pixabay

Prenatal Testing and Ataxias


If there is a known case of Ataxia in the family, it is absolutely essential for closest female relatives like siblings, uncles, aunts and cousins to test for carrier status.

If a woman with a carrier status is pregnant, prenatal test is essential to determine if the fetus has the disease mutation.

Look up our list of clinical geneticists and testing centres in India for help and support

Mail us on namitha@strandlf.org if you require any further information or want to contribute a resource for this page

Article and Journal Links:


Videos:


What is Spinocerebellar Ataxia?

What is Friedrich’s Ataxia?