Summary: Researchers have developed an RNA-based nanopore diagnostic that folds fragile RNA into stable, labeled nanostructures—an “RNA origami” approach—that can accurately detect and size dangerous repeat expansion mutations. This method addresses a major blind spot in genetic diagnostics: tandem repeat expansions that underlie disorders such as forms of muscular dystrophy, Huntington’s disease and amyotrophic lateral sclerosis (ALS). By threading these labeled RNA structures through microscopic glass nanopores, the team produced a reliable electrical readout with enough precision to distinguish healthy repeat lengths from disease-causing expansions using only tiny clinical samples.
Key Facts
- The undiagnosed majority: Repeat expansion disorders are common—affecting roughly 1 in 280 people—but many patients remain unidentified because current clinical tests struggle to size long repeats accurately. The research highlights that a large fraction of affected individuals may still be undiagnosed due to the limitations of standard assays.
- Why repeat length matters: The number of repeats directly influences disease onset and severity. For example, about 50 repeats in the DMPK gene mark the threshold for adult-onset myotonic dystrophy type 1, while modest increases above that number raise the risk of more severe, congenital forms. In congenital central hypoventilation syndrome, a difference of just six repeats can determine whether a newborn breathes normally or faces life-threatening respiratory failure during sleep.
- Limitations of PCR and routine sequencing: Polymerase Chain Reaction (PCR) and many sequencing platforms can distort or misread highly repetitive regions. Amplification bias and sequence homogeneity make accurate length determination technically challenging, which undermines reliable diagnosis and clinical decision-making.
- RNA origami and nanopore sensing: The method uses short DNA oligonucleotides to fold target RNA into predictable, labeled nanostructures. As each nanostructure passes through a glass nanopore it produces a characteristic disruption of ionic current; that electrical pattern serves as a barcode reflecting the molecule’s shape and how many repeats it contains.
- 18-nucleotide resolution: The team demonstrated repeat-size discrimination down to 18 nucleotides, a resolution sufficient to separate normal from pathogenic repeat lengths for several disease-associated loci while using minimal RNA input.
- Path toward clinical use: The approach has been validated in controlled laboratory samples and in total RNA extracted from a DM1 human cell-line model. A University of Cambridge spin-out, Cambridge Nucleomics, is working to develop and scale the platform so multiple nanopores run in parallel for routine diagnostic throughput.
Source: University of Cambridge
A multidisciplinary team led by researchers at the University of Cambridge has created a single-molecule nanopore strategy that measures native RNA tandem repeats directly. Instead of amplifying repetitive sequences, which can introduce bias and misrepresent length, the new workflow stabilizes fragile RNA into DNA-labeled nanostructures that are robust enough to be analyzed by nanopore sensing.
Repeat expansions interrupt normal cellular processes and cause a spectrum of neurological and neuromuscular conditions known collectively as repeat expansion disorders. Accurate sizing of these repeats is clinically important because small differences in repeat number can change prognosis, recurrence risk and treatment choices. The RNA origami nanopore approach aims to deliver precise sizing information from very small amounts of RNA, addressing the common clinical constraint of limited sample material.
Lead author Gerardo Patiño‑Guillén from Cambridge’s Cavendish Laboratory explains that RNA carries detailed disease information but is fragile and poorly served by methods designed for DNA. The team’s solution uses short DNA “staples” to fold and label RNA into predictable shapes that survive handling and provide consistent electrical signatures when analyzed via nanopore sensing.
In laboratory experiments, the method detected and distinguished disease-relevant repeat lengths associated with myotonic dystrophy types 1 and 2 (DM1 and DM2), and congenital central hypoventilation syndrome-1. The researchers also demonstrated compatibility with complex biological samples by applying the technique to total RNA from a DM1 cell-line model.
Although results in controlled settings are promising, the platform has not yet been validated on clinical patient samples. Scaling up—multiplexing many nanopores to achieve diagnostic throughput—is the next engineering challenge before routine clinical deployment. Cambridge Nucleomics, a spin-out co-founded by senior author Professor Ulrich Keyser, is developing the technology toward a diagnostics product intended to complement, not immediately replace, existing PCR-based tests. In the short term, the method could serve as a fast, targeted confirmatory assay for families known to carry repeat expansions or for clinicians requiring quick, precise sizing. In the longer term, it could be useful for monitoring responses to emerging disease-modifying therapies.
Patiño‑Guillén emphasizes confidence in the molecular platform’s performance on controlled samples and notes that the immediate aim is to prove equivalent accuracy on clinical material. The work was partially funded by the European Research Council, the European Union and the Engineering and Physical Sciences Research Council (EPSRC). Gerardo Patiño‑Guillén is a Member of Churchill College, Cambridge.
Key Questions Answered:
A: Standard sequencing and PCR-based tests struggle with long, homogeneous repeat regions. Amplification bias and read errors obscure true repeat length, which is critical because disease severity and onset depend on precise repeat counts. These technical limitations leave many affected individuals without an accurate molecular diagnosis.
A: Short DNA strands fold and label the target RNA into a predictable geometry. When that labeled nanostructure is driven through a nanopore, it transiently disrupts ionic current. The pattern and magnitude of those current dips form a signature that corresponds to the structure and number of repeats, allowing single-molecule sizing without amplification.
A: Not immediately. At present, the approach is a high-precision, targeted tool suited for confirming suspected repeat expansions and for rapid clinical questions. To become a routine diagnostic, the platform must be scaled to run many nanopores in parallel and validated on patient samples. Over time it could complement sequencing approaches and support therapeutic monitoring.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- The journal paper was reviewed in full.
- Additional context was added by staff.
About this genetics and neurology research news
Author: Sarah Collins
Source: University of Cambridge
Contact: Sarah Collins – University of Cambridge
Image credit: Neuroscience News
Original Research: Open access. “Quantification of disease-associated RNA tandem repeats by nanopore sensing” by Gerardo Patiño-Guillén, Jovan Pešović, Marko Panić, Max Earle, Anastasija Ninković, Sergiu Petrușca, Dušanka Savić-Pavićević, Ulrich F. Keyser & Filip Bošković. Nature Communications. DOI: 10.1038/s41467-026-72819-5
Abstract
Quantification of disease-associated RNA tandem repeats by nanopore sensing
Short tandem repeat expansions underlie a group of neurological and neuromuscular diseases known as repeat expansion disorders, yet precise characterization of these repeats remains technically challenging. Conventional amplification-based methods introduce bias and cannot reliably resolve repeat length. Here, the authors present a single-molecule nanopore-based strategy that enables direct quantification of tandem repeats in native RNA. By assembling RNA:DNA nanostructures that encode specific repeat numbers, the method achieves repeat-size discrimination with a resolution of 18 nucleotides. Using RNA containing disease-associated repeats, the study detects and discriminates clinically relevant repeat lengths for myotonic dystrophy types 1 and 2 and congenital central hypoventilation syndrome-1. Application to total RNA extracted from a DM1 human cell-line model demonstrates compatibility with complex biological samples. This approach offers a platform for studying repeat expansion biology at single-molecule resolution with potential diagnostic and research applications.