The prince had PolG disease, a genetic mitochondrial disorder that prevents the body's cells from producing adequate energy.

POLG-related diseases disrupt the function of the mitochondria, or "powerhouses" of the cell — starving them of energy.

The son of Prince Robert of Luxembourg and Princess Julie of Nassau, Prince Frederik, has died in Paris the age of 22 due to a rare genetic disorder – POLG Mitochondrial disease. At such a critical moment in US history, we need reporters on the ground. Your donation allows us to keep sending journalists to speak to both sides of the story.