About dmg
What is DMG?
Diffuse Midline Glioma (DMG) and Diffuse Intrinsic Pontine Glioma (DIPG) are rare, aggressive brain tumors primarily affecting children.
Diffuse Midline Glioma (DMG) is a broader classification introduced in 2016 by the World Health Organization (WHO). While DIPG refers specifically to tumors located in the pons, DMG encompasses a wider group of tumors that occur in midline structures of the brain and spinal cord, such as the thalamus, spinal cord, and other brainstem areas—including the pons.
The defining characteristic of DMG is the presence of a specific genetic mutation known as H3 K27M, which disrupts gene regulation and drives tumor growth.
What is DIPG?
DIPG is a type of tumor that arises in the pons, a vital part of the brainstem that controls breathing, heart rate, and basic motor functions. These tumors are highly infiltrative, meaning they spread between healthy brain cells, making surgical removal virtually impossible. DIPG is classified as a high-grade glioma and has historically been one of the most devastating pediatric brain tumors due to its location, rapid progression, and resistance to treatment.
Key Differences Between DMG and DIPG
Location
DIPG is limited to the pons. DMG includes tumors in multiple midline locations, such as the thalamus, spinal cord, and brainstem (including the pons).
Genetic Mutation
DMG is specifically defined by the H3 K27M mutation. Not all DIPGs were historically tested for this mutation, but today, those that are H3 K27M-mutant fall under the DMG classification.
Classification
DIPG is an anatomical diagnosis. DMG is a molecular diagnosis. That means DMG is defined by its genetic makeup, making it a more modern and precise classification in the era of precision medicine.
Scope
All DIPGs with the H3 K27M mutation are considered DMGs, but not all DMGs are DIPGs. DMG is the more comprehensive and current term.
key facts
DIPG and DMG are classified as grade IV tumors, meaning they are high-grade, fast-growing, and difficult to treat.
About 150–300 children are diagnosed annually in the U.S. with DIPG or DMG.
The average age of diagnosis is between 5 and 10 years old.
DIPG accounts for approximately 10–20% of all pediatric brain tumors and 40% of pediatric brain cancer deaths.
Like so many others facing DMG, Mark carried the H3K27M mutation—a defining genetic marker that has become a central focus of ongoing research and hope.
Federal funding for all childhood cancers is less than 4% of the total U.S. cancer research budget.
Prognosis
Unfortunately, the prognosis for DIPG/DMG remains extremely poor:
The median survival time is 9 months from diagnosis.
90–95% of children diagnosed will not survive beyond 2 years.
Fewer than 10% of patients survive longer than 2 years, and less than 1% survive past 5 years.
Radiation therapy is the current standard of care, offering only temporary relief of symptoms.
While new clinical trials and targeted therapies are emerging, there is still no known cure for DIPG/DMG.
What Makes DMG More Distinct?
DMG represents a shift in how we understand pediatric brain tumors—not just by where they occur, but by what drives them at the molecular level. This distinction allows for more targeted research, clinical trials, and treatment strategies. The H3 K27M mutation, which defines DMG, has opened the door to a deeper understanding of epigenetics and potential therapies aimed at reversing the effects of this mutation. In essence, DMG reflects the evolution from an anatomical diagnosis (like DIPG) to a genetically informed, biologically relevant framework that holds greater promise for future breakthroughs.
resources for families
Navigating a DIPG or DMG diagnosis is incredibly difficult, but you’re not alone. Here are trusted organizations and resources for support
The ChadTough Foundation
Accelerates research and honors the lives of children affected by DIPG through fundraising and awareness
Defeat DIPG Foundation
Funds groundbreaking research and supports families impacted by DIPG and DMG
St. Jude Children’s Research Hospital
Provides world-class care at no cost to families and leads pediatric cancer research, including brain tumors
CureSearch for Children’s Cancer
Connects families with resources and supports clinical research to accelerate cures for childhood cancers.
Children’s Brain Tumor Network
A collaborative research network providing access to biospecimens and data for brain tumor research.