Table 1.
Spinocerebellar Ataxias (SCA’s)
| Disease | Locus | Gene/Protein | Mutation (size range) |
|---|---|---|---|
| SCA1* | 6p | ATXN1/Ataxin-1 | CAG/polyQ exp. (39-82) |
| SCA2* | 12q | ATXN2/Ataxin-2 | CAG/polyQ exp. (33-64) |
| SCA3* | 14q | ATXN3/Ataxin-3 | CAG/polyQ exp. (52-86) |
| SCA4 | 16q | Unknown | Unknown |
| SCA5* | 11p | SPTBN/ Beta-III spectrin | Nonrepeat mutations |
| SCA6* | 19p | CACNA1/ Calcium channel | CAG/polyQ exp. (19-30) |
| SCA7* | 3p | ATXN7/Ataxin-7 | CAG/polyQ exp. (37-200) |
| SCA8* | 13q | SCA8 | CAG/CTG exp. (107-128) |
| SCA10* | 22q | SCA10 | ATTCT exp. (1000-4000) |
| SCA11* | 15q | TTBK2/ tau kinase | Nonrepeat mutations |
| SCA12* | 5q | PPP2R2B/posphatase | CAG exp. (66-78) |
| SCA13* | 19q | KCNC3/ potassium channel | Unknown |
| SCA14* | 19q | PKC γ/ protein kinase C | Nonrepeat mutations |
| SCA15/16 | 3p | ITPR/ IP3 receptor | Nonrepeat mutations |
| SCA17* | 6q | TBP/ TATA binding protein | CAG/polyQ exp. (50-63) |
| SCA18 | 7q | Unknown | Unknown |
| SCA19 | 1p | Unknown | Unknown |
| SCA20 | 11 | Unknown | Genomic duplication |
| SCA21 | 7p | Unknown | Unknown |
| SCA22 | 1p | Unknown | Unknown |
| SCA23 | 20p | Unknown | Unknown |
| SCA24 | 19 | Unknown | Unknown |
| SCA25 | 2p | Unknown | Unknown |
| SCA26 | 19p | Unknown | Unknown |
| SCA27* | 13q | FGF14/fibroblast growth factor | nonrepeat mutations |
| SCA28 | 18p | Unknown | Unknown |
| SCA29 | 3p | Unknown | Unknown |
Asterisks denote SCAs for which clinical genetic testing is currently available. SCAs in bold type represent CAG/polyQ diseases.
Abbreviations: polyQ: polyglutamine; exp.: expansion; IP3: Inositol-1, 4, 5-triphosphate