Clinical features: Friedreich ataxia (FRDA) is the commonest inherited cause of cerebellar ataxia and is characterized by a slowly progressive ataxia. The onset is usually before the age of 20 years, although a significant proportion (between 17% and 25%) of individuals will present after 25 years of age. Other common features of the condition include hypertrophic cardiomyopathy in about two thirds of individuals and diabetes mellitus in 10% of individuals.
Incidence: Approximately 1 in 50,000.
Inheritance: Autosomal recessive.
Gene: The commonest form of Friedreich ataxia is caused by a mutation in the frataxin (FRDA) gene on chromosome 9. About 96% of individuals with FRDA are homozygous for the common mutation, an expanded GAA triplet (trinucleotide) repeat.
Prenatal diagnosis: Possible in the majority of families. Please refer to your local clinical genetics service prior to a pregnancy. This ensures family members are offered appropriate advice and investigations, to confirm whether or not prenatal diagnosis is possible.
Carrier testing: Possible if mutations are identified in affected family members.
UK Support Group: Ataxia UK 10 Winchester House Kennington Park Cranmer Road London SW9 6EJ Tel 020 7820 3900 (Helpline) Tel 020 7582 1444 (Office) Fax 020 7582 9444 Web: www.ataxia.org.uk
If you would like to access specialist information on Friedreich ataxia please go to:- Omim - Friedreich ataxia
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