Skip to main content
Friedreich ataxia (FA) is a slowly progressive ataxia with typical onset between age 10-25 years. It is characterized by depressed tendon reflexes, speech disturbance (dysarthria), muscle weakness, visual disturbance due to optic nerve atrophy and spasticity. Individuals with FA often have diabetes mellitus and/or cardiomyopathy. For about 25% of affected individuals, the age of onset is later and progression of the disease is much slower than usual. FA is caused by a GAA expansion in the Frataxin gene. Normal GAA repeat length is 5-33 GAA repeats. 34-65 uninterrupted GAA repeats are mutable normal alleles. They do not cause disease, but may expand during transmission to the next generation and become disease-causing alleles. Disease-causing alleles have 66-1700 repeats. 96% of affected individuals are homozygous for a triplet repeat expansion. About 4% of affected individuals will have a GAA expansion on one allele and a point mutation on the other allele.
Seattle Children’s provides healthcare for the special needs of children regardless
of race, sex, creed, ethnicity or disability. Financial assistance for medically
necessary services is based on family income and hospital resources and is provided
to children under age 21 whose primary residence is in Washington, Alaska, Montana
Seattle Children’s Hospital, Research