UNC13A Fix Restores Signalling in Lab MND Models

A Nature paper published on 11 November 2026 reports that correcting a single splicing error in the gene UNC13A restored communication between human neurons in the laboratory after the proofreading protein TDP-43 had failed. The study, “UNC13A splice correction rescues synaptic dysfunction induced by TDP-43 loss,” is laboratory work only. It contains no patient data.

King’s College London, in a release of the same day, says that without TDP-43 proofreading, errors in UNC13A “drastically reduced neuron communication,” and that an antisense oligonucleotide restored “production of functional UNC13A protein, letting the neurons communicate again” — in human neurons “in the lab.” University College London issued a matching account. A related but different antisense drug, TRCN-1023, is already in a human trial and is not the molecule tested in this paper.

One UNC13A error was enough, in the lab, to restore signalling

TDP-43 is a protein that, when it stops doing its job, is a shared feature of most motor neurone disease, also called amyotrophic lateral sclerosis (ALS). King’s says there are already approved and experimental treatments for two rare genetic forms of ALS, which account for under 3% of cases, and that “there is no significant disease-modifying treatment available for the remaining 97%.” The college says the new findings “could have beneficial therapeutic implications for 97% of people with MND, for whom there is currently no significant disease-modifying treatment.” That is King’s wording about a possible implication, not a result in patients.

The Nature paper’s own summary says TDP-43 loss induces a predegenerative state in which neurons remain structurally intact and suffer a substantial breakdown in synaptic communication, and that a splice-switching antisense oligonucleotide can correct UNC13A cryptic splicing. The authors include joint first authors Matthew Keuss and Peter Harley at UCL and co-lead authors Juan Burrone at King’s and Pietro Fratta at UCL and the Francis Crick Institute, with colleagues at Leibniz-FMP and Trace Neuroscience also named by King’s. Professor Burrone said: “We were surprised to see that restoring just one genetic event, out of the hundreds disrupted, was enough to allow neurons to talk to each other again.”

Professor Fratta said: “Our previous work told us UNC13A is important in ALS progression, but we still did not know in which way and to what extent it plays a role. We have now learned it’s the main driver of synaptic release deficits upon TDP-43 dysfunction, and have developed very effective antisense oligonucleotides to rescue this deficit. Excitingly these drugs have already entered clinical trials.”

The trial drug he is pointing to must be kept separate from the laboratory result. King’s says a related antisense oligonucleotide, TRCN-1023, is in Trace Neuroscience’s Phase 1/2 FUNCTION ALS trial, and that the first UK participants were dosed last month, with UCL as a participating site. UCL says Trace Neuroscience is a biopharma company co-founded by Professor Fratta. The Nature paper does not report data from that trial, and it does not show that TRCN-1023 has restored signalling in patients.

King’s and UCL also note funding from the Medical Research Council, the MND Association, Wellcome, LifeARC and other backers, including Trace Neuroscience.

TSN’s recent science coverage includes a laboratory study mapping two toxic routes in Alzheimer’s amyloid, work on proteins made by splicing errors in lupus, and, on the ALS side but in a quite different register, a free voice-restoration scheme for people with ALS in Spain.

A restored dish is not a treatment, and TRCN-1023 is a different drug

The result to hold onto is specific and still early. In human neurons in the lab, fixing one UNC13A splicing error was enough, the authors say, to let the cells communicate again after TDP-43 had failed. That is a mechanistic finding, and it is the finding the paper actually makes. King’s 97% figure describes the share of people with motor neurone disease who today have no significant disease-modifying treatment, and a hope about implications, not a measured benefit in those people.

TRCN-1023 sits in a different column. It is already being given to participants in a Phase 1/2 trial, including in the UK last month, and it is a related but different antisense drug. The Nature study offers no patient results that can be read across to that trial, and the trial cannot be used, in the other direction, as proof of the laboratory paper. The next facts that would change the story are clinical data from FUNCTION ALS, clearly labelled as such, and any later study that tests this laboratory correction in a setting closer to a human disease course. Until then, the honest headline is a lab restoration of signalling, not a new treatment for motor neurone disease.

Sources

Matthew Keuss et al., “UNC13A splice correction rescues synaptic dysfunction induced by TDP-43 loss,” Nature, 11 November 2026, DOI 10.1038/s41586-026-11256-2. https://www.nature.com/articles/s41586-026-11256-2
King’s College London, “Potential MND therapy restores communication between human neurons in the lab,” 11 November 2026. https://www.kcl.ac.uk/news/potential-mnd-therapy-restores-communication-between-human-neurons-in-the-lab
University College London, “Potential MND therapy restores communication between human neurons in the lab,” 11 November 2026. https://www.ucl.ac.uk/news/2026/nov/potential-mnd-therapy-restores-communication-between-human-neurons-lab