| Disease ID | Source | Name | Description |
| 164400 | OMIM | Spinocerebellar ataxia 1 (SCA1) | Spinocerebellar ataxia is a clinically and genetically heterogeneous group of cerebellar disorders. Patients show progressive incoordination of gait and often poor coordination of hands, speech and eye movements, due to cerebellum degeneration with variable involvement of the brainstem and spinal cord. SCA1 belongs to the autosomal dominant cerebellar ataxias type I (ADCA I) which are characterized by cerebellar ataxia in combination with additional clinical features like optic atrophy, ophthalmoplegia, bulbar and extrapyramidal signs, peripheral neuropathy and dementia. SCA1 is caused by expansion of a CAG repeat in the coding region of ATXN1. Longer expansions result in earlier onset and more severe clinical manifestations of the disease. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by expansion of the polyglutamine tract to about 40-83 repeats, causing accumulation in neurons and exerting toxicity. |