Prince Frederik, the youngest son of Prince Robert of Luxembourg and Princess Julie of Nassau, left behind a lasting legacy following his death at age 22 this month.

The beloved royal died on March 1 from POLG Mitochondrial disease — a rare genetic disorder that affects approximately one in 5,000 people.

The genetic disorder affects multiple organ systems and the mitochondria, the energy-producing parts of cells.

Prince Frederik, the youngest son of Prince Robert of Luxembourg and Princess Julie of Nassau, left behind a lasting legacy following his death at age 22 this month. POLG Foundation

Frederik was diagnosed with the disease at the age of 14 after enduring unexplained symptoms for years.

In 2022, Frederik founded The POLG Foundation, an organization that researches the disease and searches for a cure.

Despite his short lifespan, the prince managed to create an inspiring legacy through his foundation, which his father vows to continue in his son’s name.

“He had barely been able to speak for several days, so the clarity of these words was as surprising as the weight of the moment was profound,” Prince Robert, 56, said of his late son.

“Frederik knows that he is my Superhero, as he is to all of our family, and to so very many good friends and now in great part thanks to his POLG Foundation, to so very many people the world over.”

Despite his health battle, Frederik worked tirelessly to raise awareness about the illness in a desperate bid to help others.

The beloved royal died on March 1 from POLG Mitochondrial disease — a rare genetic disorder that affects approximately one in 5,000 people. Royal Family of Luxembourg/Instagram

He then joined forces with designer Donna Karan to develop the MITO clothing line, selling items through his POLG Foundation to raise awareness and funds.

In addition, Frederik participated in medical trials which helped to develop cell lines for research across Switzerland, the US and Europe.

His work laid the foundation for The POLG Toolbox, a crucial resource for scientists, his proud father said.

Frederik was diagnosed with the disease at the age of 14 after enduring unexplained symptoms for years. Royal Family of Luxembourg/Instagram

“The POLG Foundation, in only three short years, has accomplished so very much, including funding four major research projects, totaling over $3.6 million,” said Robert, the first cousin of Grand Duke Henri of Luxembourg.

Meanwhile, Frederik’s mother, Princess Julie, had been instrumental in tasking the scientific community to push forward with research.

Despite his struggles, Frederik saw his illness as a gift and opportunity to help others.

In 2022, Frederik founded The POLG Foundation, an organization that researches the disease and searches for a cure. POLG Foundation

“Speaking to a friend of ours, he told Andrew, ‘I am glad that I am the one who was born with this disease. Even though I’ll die from it… and even if my parents do not have the time to save me, I know that they will be able to save other children,’” Robert said.

Speaking about his son’s heartbreaking final moments, Robert revealed that Frederik’s final question to him was, “Papa, are you proud of me?”

Prince Frederik had struggled to speak for “several days” before he died, according to Robert, “so the clarity of these words was as surprising as the weight of the moment was profound.”

Robert added that his son’s mission in raising awareness for the disease will continue through his organization.

Frederik also participated in medical trials which helped to develop cell lines for research across Switzerland, the US and Europe. POLG Foundation

“With our Superhero’s help, we hope to turn our deep grief into positive results and follow his unwavering example,” he said.

“His ultimate message is one of hope, compassion, and resilience. We are all so very proud of you, Frederik. I am so very proud of you. We love you.”