Spinocerebellar ataxia type 26 (SCA26) is a very rare subtype of autosomal dominant cerebellar ataxia type 3 (ADCA type 3; see this term) characterized by late-onset and slowly progressive cerebellar signs (gait ataxia) and eye movement abnormalities.
To date, only 23 affected patients have been described from one American family of Norwegian descent.
Disease onset occurs between the ages of 26-60 with a mean age of onset of 42 years. Slowly progressive gait ataxia, dysarthria, nystagmus, impaired pursuit, and dysmetric saccades were reported in all patients. Left-sided pyramidal signs (hyperreflexia with positive Babinski sign) were reported in one patient. The disease duration is unknown.
A candidate gene for SCA26 has recently been identified as the eukaryotic translation elongation factor 2 (EEF2) gene, located on chromosome 19p13.3. Further confirmatory studies are still required in order to determine if a mutation in this gene directly causes SCA26.
SCA26 is inherited autosomal dominantly and genetic counseling is possible.
Last update: November 2014
- Dr Shinsuke FUJIOKA
- Dr Zbigniew WSZOLEK
- Dr Shozaburo YANAMOTO