Expression of these mutant channels results in cells with drastically decreased current density compared to wild-type expressing cells. In cell-based assays, it was found that these mutant channels aggregate in the endoplasmic reticulum, not dissimilar from that seen in the CAG expansion mutants above. R1664Q is in the 4th transmembrane spanning segment of domain 4 and, presumably, affects the channels voltage dependence of activation. Little is known about the point mutations resulting in overlapping phenotypes of familial hemiplegic migraine and episodic ataxia. R583Q is present in the 4th transmembrane spanning region of domain 2 while the I1710T mutation is segment 5 of domain 4. Diagnosis
Spinocerebellar Ataxia Diagnosis is done via genetic testing. Your Neurologist can administer the test. Spinocerebellar Ataxia is often misdiagnosed as other diseases such as ALC or Parkinsons Disease. Screening
There is no known prevention of spinocerebellar ataxia. Those who are believed to be at risk can have genetic sequencing of known SCA loci performed to confirm inheritance of the disorder. Treatment
There are no drug based treatments currently available for SCA Type 6, however, there are supportive treatments that may be useful in managing symptoms. Physical Therapy, Speech Pathology can help patients manage the symptoms. Epidemiology
The prevalence of SCA6 varies by culture. In Germany, SCA6 accounts for 10-25% of all autosomal dominant cases of SCA (SCA itself having a prevalence of 1 in 100,000). This prevalence in lower in Japan, however, where SCA6 accounts for only ~6% of spinocerebellar ataxias.
In Australia, SCA6 accounts for 30% of spinocerebellar ataxia cases while 11% in the Dutch. See also
Calcium channel
Cerebellum
Episodic ataxia
Familial hemiplegic migraine
Huntingtons disease
Spinocerebellar ataxia

References
External links
sca6 at NIH/UW GeneTests