Prince Frederik of Luxembourg died from a genetic disease called PolG, but experts hope his passing could bring more awareness to the rare condition that impacted his life. Prince Frederik, 22, died from a mitochondrial disease known as PolG,

Prince Frederik, 22, was a founder and the creative director of a foundation that raised awareness of POLG disorder.

Affected populations: PFIC is a group of rare genetic diseases that cause progressive liver failure. The exact prevalence of PFIC is unknown, but estimates suggest that these diseases affect between 1 in 100,000 and 1 in 50,000 people worldwide. In the United States, fewer than 50,000 people total are believed to have PFIC.

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.