Simple everyday pleasures like going for a walk outside or swimming at the beach would be enough to commit twins Thomas and Vincent to “certain death”.
The 23-year-olds were born with an incredibly rare genetic disorder called Xeroderma Pigmentosum (XP) which makes them fatally allergic to ultraviolet light, including sunlight, Nine reported.
Their parents, Bernard and Françoise, both carried a genetic mutation that predisposed both sons to the condition, which is so rare it affects just one in a million.
“It’s a terminal disease for people that don’t protect themselves,” Vincent said in an episode of Nine Now’s Body Bizarre program.
The parents revealed how the boys used to play outside regularly up until about age two when they started getting red marks on their cheeks.
The red marks were later revealed to be small cancers, which ended up growing on their face, arms and legs.
While doctors predicted the twins wouldn’t survive their teenage years, the family has adopted a series of measures to limit their exposure to ultraviolet light.
Their home in France has windows with filters over them to prevent sunlight from getting inside, similar to what would protect museum exhibits from being damaged.
The light bulbs in the home have also been replaced by bulbs that don’t emit ultraviolet rays.
The only way the brothers can safely go outside is if they cover their body completely, so each of them have an ultraviolet resistant spacesuit and mask.
The mask, displayed by Vincent who has had his since he was 11, was designed by NASA.
The crucial use of all the protective measures has allowed the twins to live safely in Bordeaux, which is partially cloudy year-round but can get up to 200 days of sunshine.