Details have emerged that before the young prince and founder of a group for rare genetic disorder research died, he asked his father a profound question about life.
The royal family of Luxembourg is mourning the loss of PolG Foundation founder and creative director, Prince Frederik, who passed away at 22. The foundation confirmed his passing on its website and revealed that he spent his last days surrounded by his family.

A netizen’s comment after learning about Prince Frederik’s death, posted on March 8, 2025 | Source: Instagram/polgfoundation
According to the foundation, on February 28—Rare Disease Day—Frederik spoke individually to his brother Alexander, sister Charlotte, cousins Charly, Louis, and Donall, his brother-in-law Mansour, Aunt Charlotte, and Uncle Mark. He had already shared his deepest thoughts with his mother, who had been by his side for 15 years.
Before his final farewell, he made sure to share one last family joke. Among those final moments, his father, Prince Robert, recalled an especially emotional exchange. Frederik asked, “Papa, are you proud of me?” Robert reassured his son that he had made a profound impact in his short life.
The Royals of Luxembourg Instagram page expressed their grief through a message on the PolG Foundation’s Instagram account, “Words can’t describe how much pain I am feeling for Robert and Julie for losing their beloved son, Frederik.”
They described Frederik as an “inspiration” to young people, whose impact will continue to inspire others facing the same illness. They also sent thoughts and prayers to Charlotte and Alexander, acknowledging the pain of losing their younger brother. “Rest in peace, sweet Prince Frederik,” they wrote.
Following the announcement, tributes poured in, with many honoring Frederik’s courage and unwavering spirit. One netizen simply stated, “💚 a true superhero.” Another shared, “Difficult to find words to describe this loss. I am thinking of you all and sending love. Frederik was exceptional in the courageous way he lived with his illness, what an example to us all. 🤍”
A mourner remembered Frederik for his “charm, brilliant humor, and creative vision,” sending love in his memory. At just 14, Frederik’s world changed overnight. He went from playing football, skiing, and enjoying meals with friends to struggling to walk, stand, or digest food. Extreme exhaustion became his daily reality.
Months of uncertainty followed, with misdiagnoses adding to the fear. Finally, doctors identified the cause: Mitochondrial Disease, a rare genetic disorder caused by mutations in the POLG gene.
PolG disease is often compared to a battery that never fully recharges—cells slowly lose their ability to function, causing progressive organ failure. Though considered rare, mitochondrial diseases are now believed to affect 1 in every 5,000 people worldwide, making them the second most common serious genetic disorder after cystic fibrosis.

Prince Frederik and fashion designer Donna Karan, posted on February 24, 2022 | Source: Instagram/polgfoundation
After years in hospitals, Frederik and his family decided they couldn’t just accept the bleak outlook. They knew something had to change—not just for him, but for others facing the same disease.
Through it all, Frederik remained incredibly strong. His father reflected on the challenges his son faced. “Being confronted with such a disease at that age is, of course, incredibly tragic. All your friends start going out and exploring the world, while you are confined to your bed, losing control over your body,” Robert recounted.

Prince Robert of Luxembourg attends the 95th Oscars Governors Ball preview in Hollywood, California, on March 7, 2023 | Source: Getty Images
Frederik eventually lost the ability to eat on his own and had to be fed through an IV. “All those pleasures that connect you to the outside world slowly disappear—it’s really tough,” he said.
Robert described Frederik as an extremely social person with a large circle of friends, and was always “the life of the party, super positive and cheerful.” Given his son’s upbeat nature, he never thought he would have to worry about him. “But back then, I didn’t know where life would take us,” he recalled.

Prince Frederik sitting on the ground, posted on February 24, 2022 | Source: Instagram/polgfoundation
Despite the hardships Frederik faced, his resilience never wavered. “Precisely because of his strength, he was able to handle his fate as best as possible and even find something positive in his situation,” Robert added.
His siblings, Charlotte and Alexander, also struggled to process their brother’s illness. “At first, there was the initial shock, followed by deep sadness,” Robert shared. Despite the pain, they stood by Frederik every step of the way. Later, they became actively involved in the PolG Foundation, determined to continue his fight.

Prince Frederik being assisted while walking, posted on February 24, 2022 | Source: Instagram/polgfoundation
Research on PolG disease could help far more than just mitochondrial patients. Robert explained that mitochondria affect many parts of the body, and problems with them are linked to diseases like Parkinson’s, depression, and cancer. Mitochondrial decline also plays a role in aging, so finding solutions for these disorders could lead to breakthroughs in treating multiple conditions.
For parents facing similar challenges, Robert acknowledged, “On a personal level, it is difficult to give universal advice. Everyone is different and processes tragedy in their own way. Compassion is important. And the awareness that every story is unique.”

Prince Robert attends the Haut Brion 75th Anniversary at The Metropolitan Museum of Art in New York City on July 12, 2010 | Source: Getty Images
Robert acknowledged that, despite the hardships of Frederik’s illness, they also witnessed moments of profound compassion. During their most difficult times, the support and selflessness of others served as a powerful reminder of the goodness in people.
“The number of wonderful people we have met throughout our journey, who dedicate their lives to helping others, is incredibly humbling. It gives you hope in humanity,” he shared.

Prince Frederik smiles beside Donna Karan, posted on February 24, 2022 | Source: Instagram/polgfoundation
Still, the early days of Frederik’s diagnosis were overwhelming. Their world was consumed by hospital visits and medical procedures. Robert explained that their primary focus was on Frederik’s care, leaving them exhausted and emotionally drained, with little energy to research the disease. “We couldn’t focus on much else,” he admitted.
As Frederik’s condition stabilized, they began searching for more information. Their desperation led them to experts worldwide, attending biotech conferences, consulting pharmaceutical professionals, and connecting with funding organizations.
Over time, they built a network of specialists, which Robert felt should be shared with other affected families. He was surprised by the lack of collaboration in the medical field, where scientists, pharmaceutical companies, and funding organizations often work in isolation. Some even withhold findings to secure publications or protect their research.

Prince Robert attends the American Riviera Award tribute at the 37th Santa Barbara International Film Festival on March 4, 2022 | Source: Getty Images
To address this, Robert and his family founded the PolG Foundation in 2022, aiming to foster transparency and cooperation. “Our goal was to bring a little more heart into this field and encourage people to share their knowledge to advance research for the benefit of all patients,” he explained.
However, he clarified that the foundation’s focus is on scientific research rather than direct patient support. “As a foundation, we do not focus on patient support, but there are others who specialize in this and do truly brilliant work. They helped us as parents immensely when we were grasping at every straw in search of answers,” he said.
By promoting collaboration and open access to research, Robert hopes the foundation will accelerate treatments and drive scientific breakthroughs for families searching for answers. Frederik’s passing is the latest loss in the royal world. Last year, King Charles III’s first cousin once removed, died at 85.
Historian and author Michel de Grece passed away in a hospital in Athens, according to the Greek newspaper Ekathimerini on July 28, 2024. Known as Prince Michael, he was reportedly the last living grandson of King George I of Greece and had close ties to the British royal family.

Michel de Grece on October 22, 1998 | Source: Getty Images
The 85-year-old Greek prince was a first cousin of the late Prince Philip, Duke of Edinburgh, who was married to Queen Elizabeth II. This connection made Michel a first cousin once removed to King Charles III.

Prince Philip at the Royal Windsor Horse Show, May 10, 1991 | Source: Getty Images
Alongside his royal lineage, Michel was known for his unique personal life. In 1965, he made headlines by giving up his royal rights to marry Marina Karella, an artist and commoner.

Marina Karella and Prince Michael with the Count and Countess of Paris in Athens, Greece, on February 5, 1965 | Source: Getty Images
This significant break from royal tradition marked a turning point in Michel’s life. The couple had two daughters, Princess Alexandra and Princess Olga, and five grandchildren.

Princess Alexandra, Marina Karella, Prince Michael, and Princess Olga at the wedding of Bruno of Limburg-Stirum and Christine de Lannoy at Chateau d’Anvaing in Belgium on July 22, 1995 | Source: Getty Images
Unlike many of his royal relatives, Michel chose to stay in Greece. He remained in the country even after the failed 1967 counter-coup, during which then-King Constantine attempted to overthrow the ruling military Junta. This decision reflected his strong connection to his homeland and his dedication to Greece.

Michel de Grece at Château de Chinon, France on March 7, 2002 | Source: Getty Images
Michel’s life in Greece greatly influenced his work. The historian wrote extensively on Greek history, the Ottoman Empire, and European royalty. His passion for history was evident in his many books, which continue to be influential.

Michel de Grece in his Paris apartment on December 14, 1995 | Source: Getty Images
Beyond sharing his historical work, Michel shared stories about his family, life, and travels on his Instagram page, giving followers a glimpse into his personal experiences. He also shared his views on the British monarchy in 2021.
In one instance, Michel spoke about Charles, expressing empathy for the challenges he faced. He said, “I don’t know if he’s perfect or not…What I know is that he can hardly do better than what he does now…I think he does his best. [Queen Camilla], too. It’s very difficult.”

King Charles III and Queen Camilla wave from the Buckingham Palace balcony after their coronation in lLondon on May 6, 2023 | Source: Getty Images
Michel had no regrets about following his own path away from the royal limelight and did not feel envious of Charles’s position. “I do not envy him at all, really – poor guy. And he does it with dedication, with a sense of humor. She, too. But I would not like that job at all,” he shared.

King Charles III at his coronation with Queen Camilla in London on May 6, 2023 | Source: Getty Images
In addition to his views on the British monarchy, Michel also reflected on the state of many families today, noting that he observed a lot of “fighting each other, hating each other” within them.

Marina Karella and Prince Michael of Greece at the “Reborn Project – Ginori Art Collection” in Paris on November 2, 2021 | Source: Getty Images
He expressed his deep affection for his own family. “I created my own family, whom I adore—my wife, children, and grandchildren. That is the most important thing for me. My life has been one of experiences, of discoveries. And I’m still very curious. Now, I’m discovering technology through my grandchildren. It’s fabulous. My life has been an adventure. It still is,” he explained.

Princess Olga, Marina Karella, Prince Michael, and Princess Alexandra at a gala party in Paris on July 1, 1994 | Source: Getty Images
At the time, the details of Michel’s funeral arrangements had yet to be announced. His passing signified the end of a notable chapter in European royalty.
Michel’s unique personal choices and influential writings left a lasting legacy, ensuring his impact on Greek and European history would be remembered for years to come.