Clinical and Molecular Correlations in Spinocerebellar Ataxia Type 6

Abstract

This study provides the first detailed description of Dutch patients with SCA6. Clinical analysis identifies SCA6 as a late-onset ataxia in which eye movement abnormalities are prominent and consistent early manifestations. No single clinical sign can be considered specific for SCA6. Some patients have ataxia combined with episodic headaches or nausea, suggesting an overlap among SCA6, eposidic ataxia type 2, and familial hemiplegic migraine. Spinocerebellar ataxia type 6 accounts for approximately 11% of all Dutch families with ADCA. Analysis of SCA6 contributes further to the genetic classification of patients with ADCA, including patients without a clear family history of the disease.

Spinocerebellar ataxia type 6 and episodic ataxia type 2: differences and similarities between two allelic disorders

“…Still other studies, however, show a more complex clinical picture. Patients may initially experience episodes of ataxia and dysarthria, and/or of vertigo and nausea, accompanied by visual disturbance (such as diplopia or blurred vision), and tinnitus, lasting from minutes to days and triggered by head move-ments and physical or emotional stress (Calandriello et al, 1996;Geschwindt et al, 1997;Jodice et al, 1997;Koh et al, 2001;Sinke et al, 2001). Episodes have a variable frequency (from yearly to daily), and duration (from seconds to days).…”

“…SCA6 accounts for 1-11 % of ADCA families collected in European centres (Leggo et al, 1997;Riess et al, 1997;Stevanin et al, 1997;Takano et al, 1998;Pujana et al, 1999;Sinke et al, 2001;Silveira et al, 2002), 6-31 % in Japanese (Matsuyama et al, 1997;Takano et al, 1998;Watanabe et al, 1998;Maruyama et al, 2002) and 0-11 % in Chinese series (Tang et al, 2000;Soong et al, 2001a). As most ADCAs, SCA6 is due to expansions of a CAG repeat stretch, which is embedded in the 3) coding region of a calcium channel gene, CACNA1A, on chromosome 19p13.…”

A clinical and genetic study in a large cohort of patients with spinocerebellar ataxia type 6

“…The induction of vertigo and oscillopsia by changes of the head position can also occur in SCA6 patients. However, these extracerebellar features have been reported with different frequencies (Geschwind et al 1997;Gomez et al 1997;Harada et al 1998;Sinke et al 2001;Durig et al 2002;Yabe et al 2003).…”

Determination of Genotypic and Phenotypic Characteristics of Friedreich’s Ataxia and Autosomal Dominant Spinocerebellar Ataxia Types 1, 2, 3, and 6

“…Pontine and cerebellar atrophy are detected in cerebral MRG. In our study, in the family considered to have SCA1, the clinical findings started at around the age of 40 years with imbalance and (45,46,47,48). These findings may further be accompanied by not only vibration and proprioceptive sensorial loss, but also nystagmus (downward nystagmus), balance disorders emerging with head movements, and such extrapyramidal findings as dysphagia, bradykinesia, parkinsonism and dystonia, and eye movements may be restricted in all directions (45,46,47,48).…”