Friedreich’s ataxia is an autosomal recessive trinucleotide repeat disorder of GAA caused by the frataxin gene on chromosome 9.
Clinical manifestations of Friedreich’s ataxia include:
- Cerebellar ataxia
- Dysarthria
- Atrophy and weakness of distal extremities
- Babinski sign
- Loss of joint and vibratory senses
- Stocking and glove sensory neuropathy
- Cardiomyopathy (around 60%)
- Diabetes (around 30%, late in the disease)
- Nystagmus (occasionally)
Friedreich’s ataxia is also associated with pes cavus and scoliosis. (60%)
Onset tends to be in the teens.
There is no cure and the mean age of death is around 37.
Small print gem: Friedreich’s ataxia is caused by a point mutation rather than trinucleotide repeat in around 2% of cases.
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