September marks the beginning of a month when the global community places special focus on mitochondrial diseases. This year, World Mitochondrial Disease Week will take place from September 15–21, 2025, under the theme “Decode the Mito Puzzle – Bridging Science and Symptoms.” The idea is clear: to connect rigorous science with real patient stories and accelerate the path toward earlier diagnosis, better care, and hope for treatment.

What are mitochondrial diseases, really?

In simple terms, mitochondrial diseases are a group of disorders in which mitochondria—the organelles responsible for energy production—do not function properly. This reduced “energy supply” leads to dysfunction of cells and organs. That’s why mitochondrial diseases are multisystemic: they can affect the brain, heart, liver, skeletal muscles, kidneys, endocrine and respiratory systems—often in different combinations in different patients.

Symptoms are diverse, ranging from muscle weakness and easy fatigue to vision and hearing problems, heart and liver disorders, diabetes, seizures, developmental delay, and more. This variability is exactly what makes the “mito puzzle” so challenging for both specialists and families.

Rare, but not invisible

Although most people have never heard of them, mitochondrial diseases are estimated to affect about 1 in 5,000 people, placing them among significant genetic disorders. Scientific evidence also links mitochondrial dysfunction to more common conditions such as Alzheimer’s disease, Parkinson’s disease, diabetes, cardiovascular problems, and certain cancers—another reason why this topic matters to society as a whole.

Genetics: why is the picture so complex?

The causes may involve mutations in mitochondrial DNA (mtDNA) or nuclear DNA (nDNA). Some mutations are inherited (including maternal inheritance in the case of mtDNA), while others arise sporadically. The same genetic defect can lead to different clinical presentations in different individuals—and conversely, different mutations can result in similar phenotypes (as seen, for example, in Leigh syndrome).

This is where the key concept of heteroplasmy comes in—the coexistence of healthy and damaged mitochondria within a single cell. As discussed previously on the Mitopia blog: if healthy mitochondria predominate, the cell may function relatively normally; but once the threshold of damaged mitochondria is exceeded, clinical disease begins. In congenital mitochondrial disorders, this threshold is crossed from the very start.

The dark side

Why talk about a “dark side”? Because when energy production collapses, the body “goes dark” where demands are highest—primarily in the brain and muscles. This can mean loss of motor control, weakness, swallowing difficulties, seizures, respiratory complications, or cardiac events. Severe mitochondrial diseases often begin in childhood and represent a dramatic ordeal for patients and their families.

Where does Mitopia fit in?

While rare mitochondrial diseases involve genetic destiny, for most of us the issue is mitochondrial efficiency and a gradually accumulating dysfunction with age. Here is where Mitopia and the Fundamentals formula aim to support cellular energy, stimulate processes such as mitophagy (recycling damaged mitochondria) and biogenesis (creating new ones).

In other words: if severe mitochondrial diseases represent the darkness that follows widespread mitochondrial damage, then in everyday life most people experience a milder version of the same phenomenon—a gradual loss of mitochondrial “power.” This is precisely where Fundamentals by Mitopia finds its purpose: to keep mitochondria in balance and prevent the “energy blackout” from arriving too early.

From science to hope

Early diagnosis and genetic testing are crucial for severe mitochondrial diseases—but it is just as important for everyone to understand their own “mitochondrial economy.” Because even if not all of us face the drama of a congenital disorder, we all depend on the quality of our mitochondria.