Updated

Twin brothers Forrest and Daniel Thiess had always wanted to serve in the U.S. military, but because of a rare illness, they can’t, WKRC reported.

Both men, who live in Mason, Ohio, enlisted at the age of 17 – Forrest as a Marine, Daniel as an Army medic. That’s when they discovered their medical condition – an illness so rare, it doesn’t have a name.

The twins have a genetic mutation which causes their blood vessels to rip and shred, according to the Columbus Dispatch. After learning of their condition, the twins both underwent open heart surgeries. An additional surgery left Daniel paralyzed from the waist down, WKRC reported.

Last Saturday, a charity called The Aubrey Rose Foundation donated a handicapped-accessible Toyota Sienna to Daniel.

The Theiss family is holding an online fundraiser this month to help pay for medical bills, the Cincinnati Enquirer reported. Daniel will begin aqua therapy soon.

Click for more from WKRC.

Click for a slideshow of the twins at the Cincinnati Enquirer.