Evidence map›Paper›PMID 41131452›Full record

ArticleGenetics, selection, evolution : GSE2025

A novel frameshift variant in ALS2 associated with segmental axonopathy in Merino sheep.

Katie L M Eager, Robert D Jolly, Leah Manning, Cali E Willet, Russell G Snell, Klaus Lehnert, Natasha E Mckean, Nick W Sneddon, Brendon A O'Rourke, Keren E Dittmer and 2 more

Abstract read
In one paragraph

Article in Genetics, selection, evolution : GSE, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors.

Katie L M EagerSydney School of Veterinary Science, The University of Sydney, 425 Werombi Road, Camden, 2570, Australia. katie.eager@dpird.nsw.gov.au.ORCID http://orcid.org/0000-0002-8249-634X
Robert D JollySchool of Veterinary Science, Massey University, University Avenue, Palmerston North, 4410, New Zealand.
Leah ManningSydney School of Veterinary Science, The University of Sydney, 425 Werombi Road, Camden, 2570, Australia.
Cali E WilletSydney Informatics Hub, The University of Sydney, 1 King Street, Newtown, 2042, Australia.
Russell G SnellSchool of Biological Sciences, University of Auckland, 3A Symonds Street, Auckland, 1010, New Zealand.
Klaus LehnertSchool of Biological Sciences, University of Auckland, 3A Symonds Street, Auckland, 1010, New Zealand.
Natasha E MckeanSchool of Biological Sciences, University of Auckland, 3A Symonds Street, Auckland, 1010, New Zealand.
Nick W SneddonSchool of Agriculture and Environment, Massey University, University Avenue , Palmerston North, 4410, New Zealand.
Brendon A O'Rourke *Elizabeth Macarthur Agricultural Institute, NSW Department of Primary Industries and Regional Development, 240 Woodbridge Road, Menangle, 2568, Australia.
Keren E Dittmer *School of Veterinary Science, Massey University, University Avenue, Palmerston North, 4410, New Zealand.
Imke Tammen *Sydney School of Veterinary Science, The University of Sydney, 425 Werombi Road, Camden, 2570, Australia.
Matt Littlejohn *School of Agriculture and Environment, Massey University, University Avenue , Palmerston North, 4410, New Zealand.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundSegmental axonopathy is a recessively inherited neurodegenerative disorder that has affected Merino sheep since the early 1930s. Despite its long-standing recognition, the genetic basis of the condition remained unknown. This study aimed to identify the genetic cause of segmental axonopathy and confirm its pathological features to improve diagnostic accuracy and inform breeding strategies.

resultsWhole genome sequencing and genotyping of affected and unaffected Merino sheep identified a novel homozygous frameshift variant in the ALS2 gene that segregated with disease. RNA sequencing of cerebellar peduncle tissue confirmed the nonsense consequence on the ALS2 transcript. Histological analysis highlighted the hallmarks of the disease as large, foamy eosinophilic axonal swellings predominantly in the trigeminal ganglia, with additional degenerative changes in both the brain and spinal cord. These findings support the value of targeted sampling of sensory roots of the trigeminal nerve, spinal cord tracts, and dorsal nerve rootlets to enhance diagnostic accuracy. The same ALS2 variant was found across multiple unrelated flocks in both Australia and New Zealand, indicating a broader presence within the fine-wool Merino sheep population.

conclusionsThis study identifies a novel ALS2 frameshift variant associated with segmental axonopathy in Merino sheep and provides both genetic and histological evidence supporting its role in disease pathology. The development of a DNA diagnostic test will enable more informed breeding decisions, reduce the prevalence of this condition, and improve animal welfare and productivity in the Merino industry. Moreover, the findings offer a potential large-animal model for exploring early-onset forms of human motor neuron diseases, including amyotrophic lateral sclerosis, in which ALS2 variants are implicated.

Indexed as

Frameshift MutationNeurodegenerative DiseasesSheep DiseasesAnimalsAxonsFemaleMaleSheep

Identifiers

PMID41131452
PMCPMC12551161

What Socratic holds

Textmetadata
LicenceCC BY
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.