The 20-year-old Austin, who had been projected as a late first-round pick, underwent a standard physical at the NBA combine where his EKG test revealed an abnormality. After additional genetic tests, results came back positive for Marfan syndrome.
The recommendation was that Austin, who is 7 foot 1, quit playing basketball immediately.
"They said I wouldn't be able to play basketball anymore at a competitive level," Austin told ESPN's Holly Rowe. "They found the gene in my blood sample. They told me that my arteries in my heart are enlarged and that if I overwork myself and push too hard that my heart could rupture. The draft is four days away, and I had a dream that my name was going to be called."
Of what he's learned from this process, Austin told Rowe: "For all of my supporters, I just want to tell them sorry. I'm sorry they couldn't see me play in the NBA. But it's not the end; it's only the beginning."
Austin's mother, Lisa Green, drove through the night Friday from Kansas to Dallas to deliver the career-ending diagnosis in person. Friends and family, including Baylor coach Scott Drew and Austin's high school coaches, gathered to tell him the news.
"This is devastating news, but Isaiah has the best support system anyone could ask for, and he knows that all of Baylor Nation is behind him," Drew said in a statement. "His health is the most important thing, and while it's extremely sad that he won't be able to play in the NBA, our hope is that he'll return to Baylor to complete his degree and serve as a coach in our program."
Included in Austin's supporters was Washington Redskins quarterback Robert Griffin III, who reached out on Twitter.
Please send up a prayer for @IsaiahAustin �� who was diagnosed with a career-ending medical condition. Great Player & better person
- Robert Griffin III (@RGIII) June 22, 2014Although no team will call his name that night, NBA commissioner Adam Silver has invited Austin to the NBA draft as his guest.
Austin, for his part, was staying positive on Twitter.
Words can't explain how thankful I am for the time I had to play this wonderful sport. It changed my life forever. #NewBeginnings
- God's Child (@IsaiahAustin) June 22, 2014I would love to thank EVERYONE who has reached out to me. Toughest days of my life. But not the last! Life goes on. GOD IS STILL GREAT! ����
- God's Child (@IsaiahAustin) June 22, 2014Austin already overcame the odds to play basketball. He has been blind in his right eye since age 16 after suffering a retinal detachment and four subsequent surgeries.
He spent two seasons at Baylor, averaging 12.1 points, 6.9 rebounds and 2.4 blocks in 28.9 minutes per game.
Some athletes have died on the court as a result of Marfan syndrome and associated aortic problems, among them noted Olympic volleyball star Flo Hyman.
According to the Marfan Foundation, Marfan syndrome is a genetic disorder that affects the connective tissue that holds together all of the body's cells, organs and tissue. It also plays an important role in helping the body grow and develop properly. Because connective tissue is found throughout the body, Marfan syndrome can affect many different parts of the body.
Features of the disorder are most often found in the heart, blood vessels, bones, joints, and eyes. Some Marfan features -- for example, aortic enlargement (expansion of the main blood vessel that carries blood away from the heart to the rest of the body) -- can be life-threatening. The lungs, skin and nervous system may also be affected. Marfan syndrome does not affect intelligence.