A Guide to 15q13.3 MDS
What is 15q13.3 Microdeletion?
15q13.3 microdeletion is a genetic change that is associated with several developmental conditions. These include Intellectual Disability, Global Developmental Delay, Epilepsy, Autism Spectrum Disorder, Speech Delay, Behavioral and Mood Disorders, ADHD
We all have 46 chromosomes in our cells, which contain the DNA that provides the instructions for life. Sometimes, errors occur where small pieces of a chromosome are missing (a deletion) or have an extra copy (a duplication). These are called Copy Number Variations, or CNVs.
15q13.3 microdeletion is a CNV where a small part of the 15th chromosome is missing. The name simply refers to its location: on the long arm ("q" arm) of chromosome 15 at position 13.3. The size of this missing piece varies, and through studying these variations, current research suggests two genes that seem to be very important: OTUD7A and CHRNA7. When these genes are missing, it is more likely that a person will have symptoms (or a "phenotype") like seizures, autistic traits, developmental delay, and intellectual disability.
The way our genes work is an amazingly complex web of interactions. This complexity leads to something called incomplete penetrance and variable expressivity, which means that among people with the exact same deletion, the severity of symptoms can vary from significant to having no noticeable symptoms at all. This is why a genetic test does not define your child's future.
Conditions caused by 15q13.3 MDS
What is the current state of research?
Because 15q13.3 is a genetically associated neurodevopmental disorder, the most exciting research focuses on restoring the function of the missing genes. This is exactly the kind of work our foundation was created to promote and foster. Here is where the science is most active today:
The OTUD7A Pathway: Recent research indicates that the OTUD7A gene may be responsible for many of the neurological symptoms. It acts as a manager for a protein called Ankyrin-G, which is a master organizer for building the parts of a neuron that send fast electrical signals. When OTUD7A is missing, this process can be disrupted. Because of this connection, it’s possible that therapies targeting related pathways could be useful in treating some symptoms of 15q13.3.
The CHRNA7 Pathway: The CHRNA7 gene provides instructions for building a key brain receptor that is part of the cholinergic system, which is vital for attention, learning, and memory. When the gene is missing, this system is impaired. There is a growing body of evidence that galantamine, a drug that improves the function of these receptors, can be helpful.
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Join Simons Searchlight! This is one of the most powerful things you can do to help. Simons Searchlight is an international research program that collects medical and developmental information from families with rare genetic disorders. By contributing your information, you help researchers understand the full picture of 15q13.3, which is essential for designing future clinical trials. You are directly helping to find answers faster.
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What Can I Do Right Now?
What Does This Mean for Treatment?
We believe that we are living in an incredibly exciting time when real progress will be made to improve the lives of those living with rare genetic diseases. Advanced genetic treatments, like the customized CRISPR gene-editing therapy successfully used at Children’s Hospital of Philadelphia (CHOP) in May 2025 to treat a rare metabolic disease in an infant, are becoming a reality.
Advanced Therapeutic Approaches
It's helpful to understand two different scientific approaches to developing new medicines: small molecule drugs and genetic medicines.
Small Molecule Drugs: Conventional drugs like galantamine or tideglusib, are typically a "small molecule." It is a chemical compound designed to interact with existing proteins or receptors in the body to modify their function. For instance, it might help a receptor work more efficiently or block an enzyme from breaking down a useful chemical in the brain.
Antisense Oligonucleotides (ASOs): ASOs operate at a different biological level. They are a form of genetic medicine, made of short, synthetic strands of genetic material. Instead of interacting with a finished protein, an ASO is designed to intercept the genetic instructions (the RNA) that the cell uses to build a protein. For a condition like 15q13.3 microdeletion where one copy of a gene is missing, an ASO can be designed to target the remaining healthy copy and instruct it to produce more of the needed protein. This process is called upregulation. The promise of targeting the gene instead of the downstream effect is that we still have an incomplete picture of all the ways genes work, so targeting the source might be more effective than trying to understand the vast web of downstream interactions. The success of other ASO therapies provides a clear clinical pathway and informs our research strategy, suggesting that this is a viable and important avenue to pursue for 15q13.
Gene therapy, which aims to add functional copies of missing genes into cells, is a primary long-term goal of the foundation. We recognize that developing such treatments presents significant financial and scientific challenges.
To meet these challenges, more research is needed for doctors to develop these treatments for disorders like 15q13.3. This is why we created this foundation: to raise awareness and funds so that the next gene therapy success story can be for a person affected by 15q13.3. With the right combination of funding, research, and coordination, we believe we can make a real, positive difference in the lives of our children. Please help us make this happen.
Where can I find support and more information?
Connecting with other families and advocacy groups is crucial. Here are some of the key resources available to you:
Precision Medicine in Autism Research institute, Alberta Canada - specializing in 15q13.3 microdeletion and genetically informed treatment of Autism
Simons Searchlight: An international research program partnering with families to accelerate research into rare genetic neurodevelopmental disorders. Simons Searchlight is currently running the only research study recognized on clinicaltrials.gov for 15q13.3 microdeletion.
15q13.3 Community Facebook Group: A community-led support group for families to share experiences and find support.
Dup15q Alliance: A leading organization that supports families, promotes advocacy, and advances research for Dup15q syndrome and other related disorders, including 15q13.3 variations.
Unique - The Rare Chromosome Disorder Support Group: An international group providing high-quality information guides and family matching for any rare chromosome disorder.
Genetic and Rare Diseases Information Center (GARD): A program of the U.S. National Institutes of Health (NIH) providing reliable, easy-to-understand information about rare diseases.
National Organization for Rare Disorders (NORD): A major U.S. patient advocacy organization providing resources, assistance, and information on rare diseases like 15q13.3 MDS.