Spinocerebellar ataxias (SCA) 1, 2, 3 and 6 are the most common, autosomal dominantly inherited cerebellar degenerations. And in the Chinese population, the most common SCA is SCA3 and the frequency of SCA 3 among SCA patients is 72.5%, followed by SCA 2 that the frequency is 12% among SCA patients. For SCA 1, the frequency among SCA patients is 7%. Even SCAs are rare diseases, a significant amount of Chinese in Hong Kong still suffer from this disorders. SCA Association in Hong Kong has 88 members who are suffering from spinocerebellar degeneration, many of them have a genetic confirmation. As there are few treatments for SCAs; therefore, understanding SCAs clinical manifestation and disease mechanisms are the first step towards development of effective treatment. The objective of this study is to develop the first SCA registry in Hong Kong with bio-repository bank for clinical and genetic information as well as serum and fibroblasts.

All the members from Hong Kong SCA association will be invited and discuss the study with them. After obtaining the informed consent, their genotypes will be determined and collect clinical information. Some of the participant will have clear genotyping via Department of Health. Participants with a genetic confirmation of SCA1, 2, 3, 6, 7, 8 and 12 genes will be included in the study. The relatives of genetically confirmed participants, who also had ataxic symptoms, might be included in the study without further determination of the genotypes.

Detailed clinical history including age of onset, clinical symptoms will be collected. A detailed neurological examination with an emphasis of eye movements (such as pursuit, saccadic, and convergence eye movements). We will also perform SARA scale, a validated ataxia scale. Timed 25 foot-walk test will be performed.

Two-year annual follow-up will be arranged for recruited subject for neurological physical examination, SARA scale, in order to continue assessment for any progress change in disease stage.

Inclusion Criteria:

1. Age 18 years and above
2. Presence of symptoms and signs of ataxia
3. Definite molecular diagnosis of SCA1, 2, 3, 6, 7, 8 or 12 either in the participant or another affected family member
4. Willingness to participate in the study and ability to give informed consent

Exclusion Criteria:

1. Known recessive. X-linked, and mitochondrial ataxias

SCA association members or SCA subjects who follow-up in our clinic or refer from other clinic