Really hate to hear this news. Hopefully the young man will be able to continue his career on some level, to some extent, in some fashion. It won't be easy, though. We wish him all the best, and certainly, most of all, good health for all of his days.
Marfan's used to be a virtual death sentence for an athletic career. Even though there are ways of managing it these days and mitigating the risk, there will still be some serious limitations imposed on what he may be able to accomplish. No NBA team is going to be willing to touch him even though at least one known Marfan's sufferer, Ike Austin, played briefly in the Association after his diagnosis. But, neither Ike's head nor his game ever seemed the same post-diagnosis.
Of course, us old-timers remember the sad, cautionary tale of the legendary Flo Hyman. Flo, probably the greatest pro volleyball player ever, collapsed on the bench during a game and died a few hours later that evening of what was first thought to be a heart attack. During the autopsy, it was discovered she had undiagnosed Marfan's Syndrome. The cause of death was, in effect, a ruptured aorta that was a consequence of the Marfan's.
From Wikipedia:
On January 24, 1986, Hyman collapsed while sitting on the sidelines after being substituted out in a game against Hitachi in Matsue City. She told her team to keep fighting, then moments later slid to the floor. She was pronounced dead at 9.36pm that evening.
At first the cause of Hyman's death was stated to be a heart attack. Not fully accepting this finding, her family requested that an autopsy be performed in Culver City, California. The autopsy, which was held on January 30, dismissed the possibility of a heart attack. It found that Hyman had a very healthy heart, and instead it was determined that she had suffered from undiagnosed Marfan syndrome, which had caused a fatal aortic dissection. Apart from her height, nearsightedness, very long arms and large hands, she showed few other physical symptoms. The pathologist who performed the autopsy, Dr. Victor Rosen, said that Hyman physically had been in superb condition except for a single fatal flaw—a dime-sized weak spot in her aorta. That small spot, less than an inch above her heart, had been there since her birth, and the artery had burst at that point as she sat on the sideline in Matsue. There was a three-week-old blood clot around the tear, indicating that an earlier rip in the same spot had already begun to heal when the fatal second rupture occurred.[3][4]