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Related Experiment Video

Updated: May 30, 2026

Cerebellar Regional Dissection for Molecular Analysis

Cerebellar Regional Dissection for Molecular Analysis

Published on: December 5, 2020

Spinocerebellar ataxia type 7.

Jean-Jacques Martin¹

¹Institute Born-Bunge, University of Antwerp, Belgium. kean-jacques.martin@ua.ac.be

Handbook of Clinical Neurology

|August 11, 2011

Summary

Spinocerebellar ataxia type 7 (SCA7) is a genetic disorder characterized by progressive vision loss and ataxia, caused by expanded CAG repeats in the ataxin-7 gene. Neuropathology varies with repeat length, impacting spinocerebellar pathways and retina.

Area of Science:

Neurogenetics
Molecular Medicine
Ophthalmology

Background:

Spinocerebellar ataxia type 7 (SCA7) is a progressive neurodegenerative disorder.
It is a polyglutamine expansion disease linked to increased CAG repeats in the ataxin-7 gene.
SCA7 exhibits dominant transmission and anticipation, affecting individuals globally.

Purpose of the Study:

To detail the genetic basis and clinical spectrum of Spinocerebellar ataxia type 7.
To correlate CAG repeat length with phenotypic severity and neuropathological findings.
To highlight current research directions focusing on ataxin-7 function.

Main Methods:

Molecular genetic analysis to determine CAG repeat numbers.
Clinical assessment of visual and ataxic disturbances.

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A Simple Composite Phenotype Scoring System for Evaluating Mouse Models of Cerebellar Ataxia

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Cerebellar Regional Dissection for Molecular Analysis

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A Simple Composite Phenotype Scoring System for Evaluating Mouse Models of Cerebellar Ataxia

A Simple Composite Phenotype Scoring System for Evaluating Mouse Models of Cerebellar Ataxia

Published on: May 21, 2010

Neuropathological examination of affected tissues, including spinocerebellar tracts and retina.

In vitro studies using transfected neural cells and in vivo studies using transgenic mouse models.

Main Results:

CAG repeat numbers range from 4-18 (normal), 18-35 (asymptomatic carrier), 36-43 (slow progression, minimal retinal issues), 50-55 (classic phenotype with visual/ataxic symptoms), and >100 (severe infantile phenotype).
Phenotypic severity, including visual impairment and ataxia, directly correlates with the number of expanded CAG repeats.
Neuropathology shows atrophy in specific neural pathways and cone-rod dystrophy, with ataxin-7 inclusions present.

Conclusions:

SCA7 diagnosis relies on molecular genetics, with CAG repeat expansion being the key factor.
The number of CAG repeats dictates the severity and progression of SCA7, influencing both neurological and ophthalmological manifestations.
Ongoing research into ataxin-7 function in cellular and animal models is crucial for understanding and potentially treating SCA7.