Related Experiment Video
Updated: Jun 1, 2026

10:49
Measuring RAN Peptide Toxicity in C. elegans
Published on: April 30, 2020
Ataxin-2 repeat-length variation and neurodegeneration
Owen A Ross1, Nicola J Rutherford, Matt Baker
1Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA.
Human Molecular Genetics
|May 26, 2011
Summary
Expanded ataxin-2 (ATXN2) repeats are a significant risk factor for amyotrophic lateral sclerosis (ALS) and may predispose individuals to progressive supranuclear palsy. Caution is advised when linking specific ATXN2 repeat lengths to disease phenotypes.
Area of Science:
- Genetics
- Neuroscience
- Molecular Biology
Background:
- Expanded glutamine repeats in ataxin-2 (ATXN2) cause spinocerebellar ataxia type 2 (SCA2).
- ATXN2 repeat expansions are implicated as a risk factor for amyotrophic lateral sclerosis (ALS) through interactions with TDP-43.
- Phenotypic variability in SCA2 necessitates investigation into ATXN2 repeat length polymorphism across neurodegenerative disorders.
Purpose of the Study:
- To investigate the polymorphic nature of ATXN2 repeat length across various neurodegenerative diseases.
- To determine the association between ATXN2 repeat length and the risk of developing neurodegenerative conditions.
Main Methods:
- Genotyping of ATXN2 repeats in 3919 neurodegenerative disease patients and 4877 healthy controls.
- Logistic regression analysis to assess the correlation between repeat length and disease risk.
Main Results:
- A significantly higher prevalence of expanded ATXN2 repeat carriers (>30 units) was observed in ALS patients compared to controls (OR=5.57, P=0.001).
- Expanded ATXN2 repeats (>30 units) showed a significant association with progressive supranuclear palsy (OR=5.83, P=0.004).
- No significant association was found between expanded ATXN2 repeats and frontotemporal lobar degeneration, Alzheimer's, or Parkinson's disease compared to controls.
Conclusions:
- The study confirms ATXN2 as a key risk factor for ALS.
- Findings support the hypothesis that expanded ATXN2 repeats may increase susceptibility to other neurodegenerative diseases, notably progressive supranuclear palsy.
- The presence of expanded ATXN2 alleles in healthy individuals highlights the need for careful interpretation of repeat lengths in disease attribution.
Related Concept Videos
Huntington Disease l: Introduction
Huntington disease or HD is a progressive, fatal neurodegenerative disorder inherited in an autosomal dominant pattern.PathophysiologyIt is caused by expansion of the CAG trinucleotide repeat in the HTT gene on chromosome 4 (4p16.3), producing an abnormal huntingtin protein with an expanded polyglutamine tract. This misfolded protein disrupts cellular function, leading to neuronal death. Normal alleles have ≤26 repeats, 27–35 are intermediate (risk of expansion), 36–39 show reduced penetrance,...
Exon Recombination
The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Tetanus
Tetanus is a life-threatening neurological disorder characterized by persistent muscle contractions and spastic paralysis. It is caused by Clostridium tetani, a motile, Gram-positive, rod-shaped, obligate anaerobe. These bacteria produce terminal endospores, giving them a distinctive “lollipop” or “tennis-racket” appearance. They thrive in anaerobic environments, such as those found in deep puncture wounds.Once introduced into the body, the spores germinate into vegetative cells. These cells...
Comparing Copy Number Variations and SNPs
Sequencing of the human genome has opened up several best-kept secrets of the genome. Scientists have identified thousands of genome variations that exist within a population. These variations can be a single nucleotide or a larger chromosomal variation.
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
ATP Synthase: Mechanism
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP...
RNA Splicing
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...