Spinocerebellar ataxia type 8

General Information (adopted from Orphanet):

Synonyms, Signs: SCA8
Number of Symptoms 19
OrphanetNr: 98760
OMIM Id: 608768
ICD-10: G11
UMLs: C1837454
MeSH: C537307

Prevalence, inheritance and age of onset:

Prevalence: No data available.
Inheritance: Autosomal dominant
Age of onset: Adult

Disease classification (adopted from Orphanet):

Parent Diseases: Autosomal dominant cerebellar ataxia type 1
 -Rare eye disease
 -Rare genetic disease
 -Rare neurologic disease

Symptom Information: Sort by abundance 

(HPO:0000514) Slow saccadic eye movements 21 / 7739
(HPO:0000641) Dysmetric saccades 10 / 7739
(HPO:0000639) Nystagmus 555 / 7739
(HPO:0007772) Impaired smooth pursuit 21 / 7739
(HPO:0002311) Incoordination 84 / 7739
(HPO:0002015) Dysphagia 301 / 7739
(HPO:0000763) Sensory neuropathy rare [HPO:skoehler] 78 / 7739
(HPO:0001337) Tremor 200 / 7739
(HPO:0009830) Peripheral neuropathy 206 / 7739
(HPO:0007256) Abnormal pyramidal signs 116 / 7739
(HPO:0002073) Progressive cerebellar ataxia 27 / 7739
(HPO:0001260) Dysarthria 329 / 7739
(HPO:0001257) Spasticity 251 / 7739
(OMIM) Hypperreflexia 1 / 7739
(HPO:0002062) Morphological abnormality of the pyramidal tract 24 / 7739
(OMIM) Sensory neuropathy has been reported 1 / 7739
(OMIM) Incoordination of trunk and limbs 1 / 7739
(HPO:0001272) Cerebellar atrophy 197 / 7739
(HPO:0000006) Autosomal dominant inheritance 2518 / 7739

Associated genes:

ClinVar (via SNiPA)

Gene symbol Variation Clinical significance Reference

Additional Information:

Clinical Description OMIM Koob et al. (1999) reported a large kindred with autosomal dominant spinocerebellar ataxia. Onset of symptoms ranged from age 18 to 65, with a mean of 39 years. Dysarthria, mild aspiration, and gait instability were commonly the initial ...
Molecular genetics OMIM In 8 pedigrees with autosomal dominant spinocerebellar ataxia, Koob et al. (1999) identified a CTG repeat expansion in the ATXN8OS gene (603680.0001), which was found to be transcribed into an mRNA with an expanded CUG repeat in its ...
Diagnosis GeneReviews SCA8 is suspected [Day et al 2000] in individuals with the following: ...
Clinical Description GeneReviews Spinocerebellar ataxia type 8 (SCA8) is a slowly progressive ataxia with disease onset typically in adulthood. Onset has been reported from age one to 65 years [Day et al 2000, Juvonen et al 2000, Silveira et al 2000, Felling & Barron 2005]. The progression is typically over decades regardless of the age of onset. Common initial symptoms reported are dysarthria and gait instability [Day et al 2000, Juvonen et al 2000]. The clinical presentation is fairly consistent among most families regardless of the pathogenic threshold, and life span is typically not shortened....
Genotype-Phenotype Correlations GeneReviews Although there is a correlation between repeat number and penetrance, longer alleles in the size range from 50 to 250 CTA/CTG repeats are more often found in affected individuals than in unaffected relatives (p<0.001). ...
Differential Diagnosis GeneReviews Ataxia. SCA8 is similar to other SCAs in that it affects coordination, with oculomotor and bulbar involvement and limb and gait ataxia (see Ataxia Overview). Some distinctions exist between SCA8 and other SCAs: ...
Management GeneReviews To establish the extent of disease in an individual diagnosed with spinocerebellar ataxia type 8 (SCA8), the following are recommended:...
Molecular genetics GeneReviews Information in the Molecular Genetics and OMIM tables may differ from that elsewhere in the GeneReview: tables may contain more recent information. —ED....