Prince Frederik of Luxembourg, the son of Prince Robert of Luxembourg and Princess Julie of Nassau, has passed away at the age of 22. His father announced the news on the website of the POLG Foundation, the organization Frederik founded to support research on POLG Mitochondrial disease, the rare genetic disorder he battled. Robert described his son as a source of strength, joy, and determination, highlighting his remarkable emotional intelligence, humor, and sense of justice. In his final moments, Frederik shared heartfelt goodbyes with his family and left them with a final joke, demonstrating his enduring positivity. Just before he passed, he asked his father, “Papa, are you proud of me?”—a moment Robert described as profoundly moving. Frederik was diagnosed with POLG Mitochondrial disease at 14, a disorder that causes progressive organ failure. Despite the challenges, he remained committed to raising awareness and finding a cure, leading the mission of his foundation with passion. His father called him a “superhero” for his ability to inspire others and lead by example. Frederik previously shared his experience in a short film for the POLG Foundation, reflecting on how his world grew smaller due to the disease. Despite this, he remained determined not to let his condition define him. He is survived by his parents, his siblings Prince Alexander and Princess Charlotte, and extended family, who continue to honor his legacy.