Abstract
Spinocerebellar ataxia-type 7 (SCA7) is a progressive autosomal dominant neurodegenerative disorder characterized by cerebellar ataxia associated with progressive macular dystrophy. The disease primarily affects the cerebellum and retina and is caused by expansion of an unstable trinucleotide CAG repeat on chromosome 3 which encodes a polyglutamine tract in the corresponding protein, ataxin-7. Pathological alleles contain from 36 to 306 CAG repeats. The clinical hallmark of SCA7 is the association of hereditary ataxia together with progressive visual loss caused by pigmentary macular degeneration. This association represents a distinct disease entity originally classified as an autosomal dominant cerebellar ataxia type II by Anita Harding.
This chapter contains a video segment which can be found at the URL: https://doi.org/10.1007/978-1-60327-426-5_101
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsReferences
McLaughlin ME, Dryja TP. Ocular findings in spinocerebellar ataxia type 7. Arch Ophthalmol. 2002;120:655–9.
Harding AE. The clinical features and classification of the late onset autosomal dominant cerebellar ataxias: a study of 11 families, including descendants of the ‘the Drew family of Walworth’. Brain. 1982;105:1–28.
Enevoldson TP, Sanders MD, Harding AE. Autosomal dominant cerebellar ataxia with pigmentary macular dystrophy. A clinical and genetic study of eight families. Brain. 1994;117:445–60.
Author information
Authors and Affiliations
Electronic Supplementary material
Clip 1: examination of the index patient shows mild cerebellar dysfunction with slight finger-nose ataxia, normal rapid alternating movements, a mildly wide-based gait, and difficulty with tandem gait. Clip 2: examination of the index patient’s nearly blind son shows ophthalmoplegia in all directions of gaze with difficulty generating saccadic and pursuit eye movements. Rapid alternating hand movements are slow, and severe finger-nose ataxia is present which appears at least in part due to poor vision. There was severe truncal and gait ataxia requiring assistance with walking.
SCA type 7.mp4 (MP4 65,548KB)
Rights and permissions
Copyright information
© 2012 Springer Science+Business Media New York
About this chapter
Cite this chapter
Bhidayasiri, R., Tarsy, D. (2012). Spinocerebellar Ataxia-Type 7. In: Movement Disorders: A Video Atlas. Current Clinical Neurology. Humana, Totowa, NJ. https://doi.org/10.1007/978-1-60327-426-5_101
Download citation
DOI: https://doi.org/10.1007/978-1-60327-426-5_101
Published:
Publisher Name: Humana, Totowa, NJ
Print ISBN: 978-1-60327-425-8
Online ISBN: 978-1-60327-426-5
eBook Packages: MedicineMedicine (R0)