Spinocerebellar ataxia type 6

General Information (adopted from Orphanet):

Synonyms, Signs: SCA6
Number of Symptoms 15
OrphanetNr: 98758
OMIM Id: 183086
ICD-10: G11
UMLs: C0752124

Prevalence, inheritance and age of onset:

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

Disease classification (adopted from Orphanet):

Parent Diseases: Autosomal dominant cerebellar ataxia type 3
 -Rare eye disease
 -Rare genetic disease
 -Rare neurologic disease

Symptom Information: Sort by abundance 

(HPO:0000640) Gaze-evoked nystagmus 27 / 7739
(HPO:0007772) Impaired smooth pursuit 21 / 7739
(HPO:0007670) Abnormal vestibulo-ocular reflex 3 / 7739
(HPO:0002076) Migraine rare [HPO:skoehler] 41 / 7739
(HPO:0000763) Sensory neuropathy 78 / 7739
(HPO:0002015) Dysphagia 301 / 7739
(HPO:0001260) Dysarthria 329 / 7739
(HPO:0002073) Progressive cerebellar ataxia 27 / 7739
(OMIM) Selective loss of cerebellar Purkinje cells 1 / 7739
(OMIM) Ccerebellar ataxia 1 / 7739
(OMIM) Hemiplegic migraine in some patients 1 / 7739
(HPO:0001272) Cerebellar atrophy 197 / 7739
(HPO:0000006) Autosomal dominant inheritance 2518 / 7739
(HPO:0003676) Progressive disorder 148 / 7739
(HPO:0003743) Genetic anticipation 9 / 7739

Associated genes:

ClinVar (via SNiPA)

Gene symbol Variation Clinical significance Reference

Additional Information:

Clinical Description OMIM Subramony et al. (1996) described a family segregating late-onset progressive cerebellar ataxia with onset of gait difficulties at age 50. There was no pontine atrophy at autopsy nor was there evidence of hypogonadism. The segregation appeared to be ...
Genotype-Phenotype Correlations OMIM Schols et al. (1997) compared clinical, electrophysiologic, and MRI findings to identify phenotypic characteristics of genetically defined SCA subtypes. Slow saccades, hyporeflexia, myoclonus, and action tremor suggested SCA2. SCA3 (109150) patients frequently developed diplopia, severe spasticity or pronounced ...
Molecular genetics OMIM Zhuchenko et al. (1997) performed a genotyping survey using polymorphic CAG repeats and DNA samples from patients with late-onset neurogenic diseases. In the course of these studies they found an expansion of a CAG repeat in the human ...
Population genetics OMIM Riess et al. (1997) found that the SCA6 mutation accounts for approximately 10% of autosomal dominant SCA in Germany.

Studying 77 German families with autosomal dominant cerebellar ataxia of SCA types 1, 2, 3, and 6, ...

Diagnosis GeneReviews Spinocerebellar ataxia type 6 (SCA6) is suspected in individuals with adult-onset, slowly progressive cerebellar ataxia, dysarthria, and nystagmus. Because the phenotypic manifestations of SCA6 are not specific, the diagnosis of SCA6 rests on molecular genetic testing. ...
Clinical Description GeneReviews Spinocerebellar ataxia type 6 (SCA6) is characterized by adult-onset, slowly progressive cerebellar ataxia, dysarthria, and nystagmus. The range in age of onset is from 19 to 71 years. The mean age of onset is between 43 and 52 years. Age of onset and clinical picture vary even within the same family; sibs with the same size full-penetrance allele may differ in age of onset by as much as 12 years, or exhibit, at least initially, an episodic course [Gomez et al 1997, Jodice et al 1997]. ...
Genotype-Phenotype Correlations GeneReviews Heterozygous individuals. Although the age of onset of symptoms of SCA6 correlates inversely with the length of the expanded CAG repeat, the same broad range of onset has been noted for individuals with 22 CAG repeats, the most common disease-associated allele [Gomez et al 1997, Schols et al 1998]. In the few individuals with (CAG)30 or (CAG)33, onset has been later than in individuals with (CAG)22 and (CAG)23 [Matsuyama et al 1997, Yabe et al 1998]. A recent retrospective study showed even closer correlation of age of onset with the sum of the two allele sizes [Takahashi et al 2004]. ...
Differential Diagnosis GeneReviews Individuals with spinocerebellar ataxia type 6 (SCA6) may present with unexplained ataxia that is part of the larger differential diagnosis of hereditary and acquired ataxias (see Ataxia Overview)....
Management GeneReviews To establish the extent of disease in an individual diagnosed with spinocerebellar ataxia type 6 (SCA6), the following evaluations 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....