Photo Credit: Shalev Cohen
Scientific Frontline: Extended "At a Glance" Summary: Non-Coding Genetic Origins of Neonatal Diabetes
The Core Concept: Researchers have established that mutations in non-protein-coding genes—specifically those responsible for producing functional RNA molecules—are a direct cause of autoimmune neonatal diabetes in infants.
Key Distinction/Mechanism: Historically, genetic disease research has focused heavily on "coding" genes that produce proteins. This discovery demonstrates that mutations in two specific non-coding genes trigger a cascading disruption of approximately 800 other genes. Many of these disrupted genes are linked to the immune system, ultimately causing it to mistakenly attack insulin-producing beta cells in the pancreas, similar to the mechanism seen in type 1 diabetes.
Major Frameworks/Components:
- Whole-Genome Sequencing: Comprehensive DNA analysis utilized to look beyond standard protein-coding regions to identify structural anomalies in the genome.
- RNU4ATAC and RNU6ATAC Genes: The specific non-protein-coding minor spliceosome components where the bi-allelic variants (mutations) occur.
- Functional RNA Deregulation: The mechanism by which the altered RNA fails to properly regulate and interpret genetic information, leading to the massive downstream disruption of immune-related genes.
- Autoimmune Beta-Cell Destruction: The ultimate physiological result where the immune system attacks the cells responsible for blood sugar regulation.
Branch of Science: Genomics, Molecular Biology, Immunology, Endocrinology, and Medical Genetics.
Future Application: By analyzing how these 800 secondary genes are disrupted, researchers can identify new biological pathways and develop targeted drugs for the much more common type 1 diabetes. Furthermore, expanding genetic diagnostics to include non-coding DNA provides a new framework to diagnose up to 50% of patients with rare genetic diseases who currently lack an accurate diagnosis.
Why It Matters: This research marks the first time that DNA changes in non-protein-coding genes have been proven to cause neonatal diabetes. It fundamentally shifts the paradigm of genetic disease screening, proving that the "overlooked" non-coding regions of the human genome hold critical answers for rare, undiagnosed autoimmune and developmental conditions.
Scientists have found new genetic causes for diabetes in babies – in a part of the genome that has historically been overlooked in genetic studies.
Until recently, most research has investigated causes of disease in ‘coding’ genes – those that produce proteins. Now, academics at the University of Exeter and their international collaborators have found that DNA changes in two genes that instead make functional RNA molecules are a cause of diabetes. RNA plays various roles in the body, including regulating genes and influencing how genetic information is “read” and interpreted.
In work supported by the National Institute for Health and Care Research (NIHR Exeter Biomedical Research Centre and the Exeter NIHR Clinical Research Facility, the team used genome sequencing, a method that reads all the letters in a person’s DNA. They found that changes in two genes called RNU4ATAC and RNU6ATAC were the cause of autoimmune neonatal diabetes in 19 children. The children in the study were identified through the University of Exeter’s work in offering free genetic testing to children thought to have genetic forms of diabetes across the world.
Neonatal diabetes is a rare form of diabetes that occurs within the first six months of life and is caused by genetic changes. Understanding the cause unlocks the potential for new treatments and better care. The research also helps give more insight into the possible causes of rare disease, which affects one in 17 people.
Study lead Associate Professor Elisa De Franco, of the University of Exeter Medical School, said “For the first time, we found that DNA changes in non-protein coding genes cause neonatal diabetes. This shows the importance of non-protein coding genes and their potential to cause disease in humans. With up to half of individuals with rare diseases currently living without a diagnosis, exploring the non-coding DNA can provide answers for families with rare conditions”
The researchers found that the 19 children all had an autoimmune form of diabetes, in which the immune system attacks insulin-producing beta cells that regulate blood sugar. This also occurs in type 1 diabetes. The team used state-of-the-art laboratory and computational methods to analyze the children’s samples and found that the mutation in the two non-coding genes was causing disruption to around 800 other genes, many linked to the immune system.
Dr James Russ-Silsby, of the University of Exeter, co-first author of the study, said: ‘Combining the DNA sequencing results with detailed analyses of the patients’ blood samples gave us a much deeper view of how these DNA changes play out inside the cell. This is helping us understand how these DNA changes result in diabetes.”
Dr Matthew Johnson, Senior Research Fellow at the University of Exeter and co-first author of the study, said “This finding is important as highlights that one or more of these 800 genes has a central role in the development of autoimmune diabetes, and could uncover new biology and potential drug targets for more common type 1 diabetes.
“Whilst the condition caused by these genetic changes is rare, it provides us with unique opportunities to study the pathways that lead to autoimmune forms of diabetes in humans, giving us a window into the ways type 1 diabetes can develop”.
Funding: National Institute for Health and Care Research (NIHR Exeter Biomedical Research Centre and the Exeter NIHR Clinical Research Facility
Published in journal: American Journal of Human Genetics
Authors: Matthew B. Johnson, James Russ-Silsby, Paul A. Blair, Molly Govier, Georgia Bonfield, Clara Domingo-Vila, EXE-T1D Consortium, ATAC Clinical Consortium, Matthew N. Wakeling, Richard A. Oram, Sarah E. Flanagan, Timothy I.M. Tree, Kashyap A. Patel, Andrew T. Hattersley, and Elisa De Franco
Source/Credit: University of Exeter | Louise Vennells
Reference Number: geno041026_01
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