Oxygen (2010)

Professor Duhamel takes great but heartless interest in the rare case of a mutated, yet congenital long disease of shy 'good boy' Lucas, father Karl's pride, and his rebellious brother Tom, who decides to enjoy as much as possible his short-cut life with dubious buddy Jimmy. Lucas dies in a promising transplant, Tom finds an apparent soul-mate in older Xavier, on the same donor list. Over a few years, doomed passion with two girls, one of which is in a bubble on account of an uncontrolled infection, messes up their relationships and even Tom's will to live, while Jimmy spares no effort or victim for his buddy's chances.