Prince Frederik of Luxembourg died at the age off 22 last month from a rare genetic disorder, his parents Prince Robert and Princess Julie confirmed over the weekend.
The young royal passed away on Feb. 28 after a long battle with PolG, a genetic mitochondrial disease that inhibits the body’s ability to produce energy, and can lead to organ failure among other serious complications, including the deterioration of brain, nerve, liver, intestinal, muscular and eye function.
In a statement posted to the PolG Foundation’s website, a charitable organization founded by the late prince, his parents said Frederik fought “valiantly until the very end.”
“His indomitable lust for life propelled him through the hardest of physical and mental challenges,” it continued, ones that his family says he fought with “grace” and “humour.”
Frederik was born with the disease but was only diagnosed at 14, when it had developed into a more acute stage and symptoms began to present themselves.

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There are 300 million people with PolG worldwide, many of whom are unaware they have the disorder, as it can be very difficult to diagnose. There is currently no treatment or cure.
“One might compare it to having a faulty battery that never fully recharges, is in a constant state of depletion and eventually loses power,” the statement explained.
Sir Douglas Turnbull, a professor and member of The POLG Foundation Scientific Advisory Board, cited PolG as the worst of all mitochondrial diseases.
“I have looked after literally hundreds of patients with mitochondrial disease and there is little doubt that of all mitochondrial diseases, POLG deficiency is the worst. It is so relentlessly progressive, attacking so many different systems with sadly the same conclusion,” he said.
The statement also credited Frederik’s mother for “working indefatigably” for 15 years to take care of her son and for her ongoing efforts to instill a sense of urgency in the global scientific community to create treatments for the fatal disease.
“Beyond this tireless work, his mother attended, organized, and animated conferences globally to encourage advancement and collaboration in POLG research,” the statement said.
In the three years since its establishment, the POLG Foundation has funded four major projects totalling over $3.6 million USD, in turn stimulating research activity in the field. It has also partnered with medical organizations around the world to create data collection tools for drug development and clinical trials, and is creating multiple films, including a cartoon series, to educate and spread awareness of the disorder.
The family credits Fredrik for his ability to see “beauty in everything.” During a recent hospital stay, Frederik’s sibling, Alexander, recalls his late brother’s request to take a photograph of the sunset through a small window in the hospital.
“Through the small, mesh-covered window, he saw the Eiffel Tower glistening with its hourly dance of lights,” the statement reads.
Similarly, written on his phone the family found notes that Frederik had written to himself.
“Go outside when the sun is shining,” one said.
“We will strive to follow his instructions, especially now that everything feels a little colder and darker in his absence,” the statement concluded.
Frederik is survived by his brother Alexander, sister Charlotte, and both his parents.