Who Was Prince Frederik of Luxembourg? The Rare Disease That Took His Life, His Lasting Impact, Net Worth

Prince Frederik of Luxembourg, the youngest son of Prince Robert and Princess Julie of Nassau, passed away on 1 March 2025 at the age of 22. On 7 March, the royal family announced his death on their POLG foundation page, saying, 'It is with a very heavy heart that my wife and I would like to inform you of the passing of our son, The POLG Foundation Founder and Creative Director, Frederik.' He was reportedly in Paris when he took his last breath.

According to reports, Frederik passed away after battling a rare genetic condition, POLG Mitochondrial disease, a disorder that caused progressive organ failure. Unfortunately, the condition currently has no effective treatments and no cure.

Despite the devastating effects of this illness, Frederik is remembered for his remarkable strength, resilience, and unwavering commitment to raising awareness about his disease. Here's a look into his life, his final moments, and the lasting legacy he leaves behind.

Frederik's Life Was Marked by Courage and Compassion

Born into the Grand Ducal family of Luxembourg, Prince Frederik was known for his royal status and charming and compassionate personality.

His father, Prince Robert, the first cousin of Grand Duke Henri of Luxembourg, described him as a person of immense strength and resilience. He also shared that his siblings Princess Charlotte Katherine Justine Marie of Nassau and Prince Alexandre Théodore Charles Marie of Nassau would often say that 'Frederik is the strongest person that we know!'

Prince Robert said, 'He was disciplined and organised beyond belief.' He also added that Frederik's compassion was 'off the charts.'

According to his family, despite suffering from a rare illness, Frederik's light and thunder never shied away, and his sense of humour remained a source of comfort until his passing.

The Rare Disease That Caused His Death

Frederik was born with POLG Mitochondrial disease, a rare genetic disorder which eventually went on to shape his life undeniably. However, it wasn't until he was 14 that he was diagnosed when the symptoms became more pronounced.

'Frederik was diagnosed with POLG at the age of 14 when his symptoms were showing more clearly and when the progression of his disease had become more acute,' Prince Robert shared in his statement, adding that the disease then started causing severe damage to Frederik body's vital organs, including his brain, muscles, and liver.

According to the POLG Foundation website, POLG Mitochondrial disease is a debilitating condition that leads to organ dysfunction and failure.

In his statement, Frederik's father wrote, 'As is the case for 300 million people like Frederik worldwide, these diseases are usually hard to recognise even by physicians, and patients' families may never know what they are suffering from as they may only be identified very late in their progression.' He added, 'One might compare it to having a faulty battery that never fully recharges, is in a constant state of depletion and eventually loses power.'

Founding the POLG Foundation

One of Frederik's most significant achievements was his involvement in the POLG Foundation, an organisation dedicated to funding research into POLG Mitochondrial disease.

In his statement, Prince Robbert said, 'The POLG foundation is committed to finding therapies and a cure to save other patients from suffering what Frederik and our family have endured.' Frederik's journey with the disease inspired him to take action, and he worked tirelessly to help others affected by the same rare disorder.

His father, Prince Robert, has been vocal about Frederik's work with the foundation. 'Frederik was not just battling the disease for himself,' Robert said. 'He was fighting for all those who shared his condition, and his contributions will continue to make a difference.'

Prince Frederik's Net Worth

While Prince Frederik's net worth is not officially known, his family's wealth provides some context.

His father, Prince Robert, is the first cousin of Grand Duke Henri of Luxembourg, who ascended to the throne in 2000. According to reports, Grand Duke Henri is one of the richest royals in the world, with an estimated net worth of around $4 billion.

Prince Robert himself holds a prominent position as the president of Domaine Clarence Dillon, a prestigious French wine company founded by his maternal great-grandfather, Clarence Dillon. As of November 2024, Prince Robert ranks 15th in the line of succession to the Luxembourg throne.

In 2022, Prince Robert made headlines when he auctioned his wine cellar at Sotheby's for an impressive $6.2 million (£4.9 million). The amount was donated to support medical research for mitochondrial-related conditions, which Frederik has been dealing with.

Although Frederik was not publicly involved in managing the family's wealth, his background and connection to Luxembourg's royal family placed him within great affluence.

Frederik's Final Moments

While sharing the memory of Frederik's final goodbye to his family, Prince Robert wrote, 'Last Friday, 28 February, on 'Rare Disease Day,' our beloved son called us into his room to speak to him for one last time.'

His father shared that Frederik had the clarity to ask him a deeply emotional question: 'Papa, are you proud of me?' To this, Robert replied, 'He had heard it oh so many times, but at this time, he needed reassurance that he had contributed all that he possibly could in his short and beautiful existence.'

Although Prince Frederik's life was cut tragically short, his legacy will continue to inspire. '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,' his father shared.