Repeat expansion target loci for CAs and clinically significant noncerebellar ataxia conditions (non-CAs), adapted from Tankard et al. (2018) and Depienne and Mandel (2021)
| Gene | Disease | Inheritance | Repeat motif | Pathogenic threshold | |
|---|---|---|---|---|---|
| CA | ATXN1 | SCA1 | AD | (CAG)n | >38 |
| ATXN2 | SCA2 | AD | (CAG)n | >31 | |
| ATXN3 | MJD; SCA3 | AD | (CAG)n | >54 | |
| CACNA1A | SCA6 | AD | (CAG)n | >19 | |
| ATXN7 | SCA7 | AD | (CAG)n | >36 | |
| ATXN8/ATXN8OS | SCA8 | AD | (CAG)n/(CTG)n | >73 | |
| ATXN10 | SCA10 | AD | (ATTCT)n | >280 | |
| PPP2R2B | SCA12 | AD | (CAG)n | >42 | |
| TBP | SCA17 | AD | (CAG)n/(CAA)n | >42 | |
| FGF14 | SCA27B | AD | (GAA)n | >249b | |
| BEAN1 | SCA31 | AD | (TGGAA)na | >109 | |
| NOP56 | SCA36 | AD | (GGCCTG)n | >649 | |
| DAB1 | SCA37 | AD | (ATTTC)na | >30 | |
| ATN1 | DRPLA | AD | (CAG)n | >47 | |
| RFC1 | CANVAS | AR | (AAGGG)n/othersa | >249 | |
| FXN | FRDA | AR | (GAA)n | >65 | |
| FMR1 | FXTAS | XLD | (CGG)n | 55–200 | |
| Non-CA | FMR1 | FXS | XLD | (CGG)n | >200 |
| AR | SMAX1; SBMA | XLR | (CAG)n | >37 | |
| C9orf72 | FTDALS1 | AD | (GGGGCC)n | >30 | |
| HTT | HD | AD | (CAG)n | >35 | |
| DMPK | DM1 | AD | (CTG)n | >49 | |
| CNBP | DM2 | AD | (CCTG)n | >50 |
[i] aRepeat motif not found in GRCh38 reference at this locus.
[ii] bIntermediate expansion range of uncertain significance 180–249.