He was the third son of Prince Robert, cousin of Grand Duke Henri of Luxembourg. The death of Prince Frederik of Nassau, at the age of 22, has caused deep sadness in the Grand Duchy of Luxembourg, but also among citizens worldwide who have been touched by his story.

Prince Frederik, the son of Europe's Prince Robert of Luxembourg, has died from a rare genetic disease, his family announced.

Prince Frederik of Luxembourg died at 22 after years of struggling with the rare mitochondrial disease PolG, according to a statement issued by his parents, Prince Robert and Princess Julie, on Monday.

Prince Frederik of Luxembourg died on March 1, his family wrote in an emotional statement last week. He was 22. The young prince, who is the son of Prince Robert of Luxembourg and Princess Julie of Nassau,

The royal family of Luxembourg is currently in mourning, as Prince Frederik of Luxembourg—the youngest son of Prince Robert of Luxembourg and Princess Julie of Nassau—has died at 22 from complications of a rare genetic disorder called POLG mitochondrial disease.

Prince Frederik of Luxembourg has died at 22 from POLG mitochondrial disease, a genetic disorder he has had since birth. The family announced his death one day after Rare Disease Day, which is the last day of February.