|
| Disease | Sites of neuropathology | CAG triplet number | Gene product (Intracellular localization of protein deposits) | Reference |
| Normal | Disease |
|
| Corea major or Huntington’s disease (HD) | Striatum (medium spiny neurons) and cortex in late stage | 6–35 | 36–121 | Huntingtin(n, c) | [49] |
|
| Spinocerebellar Ataxia Type 1 (SCA1) | Cerebellar cortex (Purkinje cells), dentate nucleus, and brainstem | 6–39 | 40–81 | Ataxin-1 (n, c) | [50] |
|
| Spinocerebellar Ataxia Type 2 (SCA2) | Cerebellum, pontine nuclei, substantia nigra | 15–29 | 35–64 | Ataxin-2 (c) | [51] |
|
| Spinocerebellar Ataxia Type 3 (SCA3) or Machado-Joseph disease (MJD) | Substantia nigra, globus pallidus, pontine nucleus, cerebellar cortex | 13–42 | 61–84 | Ataxin-3 (c) | [52] |
|
| Spinocerebellar Ataxia Type 6 (SCA6) | Cerebellar and mild brainstem atrophy | 4–18 | 21–30 | Calcium channel subunit (α1A) (m) | [53] |
|
| Spinocerebellar Ataxia Type 7 (SCA7) | Photoreceptor and bipolar cells, cerebellar cortex, brainstem | 7–17 | 37–130 | Ataxin-7 (n) | [54] |
|
| Spinocerebellar Ataxia Type 12 (SCA12) | Cortical, cerebellar atrophy | 7–32 | 41–78 | Brain-specific regulatory subunit of protein phosphatase PP2A (?) | [55] |
|
| Spinocerebellar Ataxia Type 17 (SCA17) | Gliosis and neuronal loss in the Purkinje cell layer | 29–42 | 46–63 | TATA-binding protein (TBP) (n) | [56] |
|
| Spinobulbar Muscular Atrophy (SBMA) or Kennedy disease | Motor neurons (anterior horn cells, bulbar neurons) and dorsal root ganglia | 11–34 | 40–62 | Androgen receptor (n, c) | [57] |
|
| Dentatorubral-pallidoluysian atrophy (DRPLA) | Globus pallidus, dentatorubral and subthalamic nucleus | 7–35 | 49–88 | Atrophin (n, c) | [58] |
|
