[MIM 109 150]

(SCA3)

Prevalence: 1 to 2/100,000; but the prevalence is higher in Azores, Portugal, Germany and The Netherlands. Best-known form of autosomal dominant cerebellar ataxia type 1. Autosomal dominant transmission with complete penetrance and anticipation phenomenon: the disease is due to an abnormal expansion of CAG trinucleotides  in the ATXN3 gene (14q21). Disease occurs if there is more than 64 repetitions of CAG.

There are 3 forms of this neurodegenerative condition with ataxia and progressive external ophthalmoplegia associated with other neurological problems:

-        1: onset in adolescence; ataxia, ophthalmoplegia, spasticity and tendinous hyperreflexia as well as dystonia and movement disorders

-        2: onset in adulthood; ataxia, dystonia, spasticity

-        3: onset after 40 years; ophthalmoplegia and signs of spinal anterior horn neurons involvement: fasciculations, muscle atrophy and weakness

Anesthetic implications:

spasticity, dystonic movements

References : 

Updated: November 2016