Isaiah Austin believed he was destined to play in the NBA, but a diagnosis took him down a different path. (5:20)

ISAIAH AUSTIN THOUGHT he was arriving at a surprise party. It was June 21, 2014 -- five days before the NBA draft. Everyone believed Austin's name would be called early in the night, so when he pulled onto his street in Dallas and saw the cars belonging to his coaches, his agent, his parents, surely it meant a team had committed to him early. Everyone must be there to celebrate what he'd been working toward his whole life.

He opened the door but no music was playing. No one was laughing or joking. He scanned the room, saw every face was somber and silent. His eyes met his mother's, and they were full of tears. He started taking a mental inventory of everyone who was there as he walked toward his mother, assuming someone must be hurt or worse.

"I'm sorry," his mother said through the tears.

Austin suddenly realized what was happening: He wouldn't be playing in the NBA. Everything went black. He slid down the wall, crumpling in on himself like a flower blooming in reverse.

With five years having passed since that day, he sometimes still lets himself imagine the life he once believed ordained for him: to be dominating in the NBA at a time when the game had evolved to revere players of his size who can stretch the floor and put up big numbers on blocks.

But a single spontaneous mutation had occurred on his 15th chromosome in utero. Twenty-one years later, as he prepared for NBA commissioner Adam Silver to call his name from the draft podium in June 2014, someone noticed. Suddenly, the sport that he'd built his future upon became something that could take his life.

Bill Roach for ESPN

THE FIRST LETTER on college stationery came when he was in seventh grade. It was from UCLA, and it was handwritten.

It's not unusual to hear a seventh-grader say they want to play in the NBA. Maybe it will earn him a pat on the shoulder, a wistful smile, some advice about a backup plan. But Isaiah Austin wasn't an average seventh-grader. For one thing, he was 6-foot-4.

Everything was lining up. Austin's team made it to the city championship game his eighth-grade year. It was a rivalry game, and the gym was packed even before warm-ups began. Austin's mom, Lisa Green, and her husband, Ben Green, whom Austin considers his father, sat in the stands with his AAU coach.

A now-6-foot-8 Austin could dunk the ball easily, but he'd never really let himself jam it down with authority. Maybe it was the hype of the crowd, or a desire to stoke the rivalry, but without much thought either way, he went in the layup line with the long, easy strides of a predator and came down hard enough to rip the rim off.

For a split second -- like driving under an overpass in the pouring rain -- the gym went silent, and then erupted. Austin didn't hear the crowd, though. He was seeing red. Not out of anger -- not even figuratively at all.

"I came down, and it was just like a red curtain was immediately placed over the vision of my right eye," Austin said.

He waited through the game, expecting it to go away. Austin's team won, and when he and his parents got back home, he told them something was wrong. His parents rushed him to the doctor, where they discovered his retina was torn nearly all the way through. He would need surgery right away.

Austin's family assumed it was related to an incident from years earlier. When Austin was 11, he was playing first base at a baseball camp. The pitcher threw to him, and Austin put his glove up a beat too late. The ball glanced off his glove and hit him in the right eye. It swelled shut.

Now, Austin's first thought at the idea of surgery wasn't fear; he was grateful. The basketball season had just ended, and he wouldn't have to miss any games for the surgery and rehab. But for the first time -- though certainly not the last -- things didn't go to plan for Isaiah Austin.

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Two years and four surgeries later, Austin was blind in his right eye. For nearly a year, he had spent most of the day and night face down in a contraption to help his eye heal properly, a tilted mirror underneath him to reflect the television or his family. To this day, he can't stand to lie on his stomach.

"We would practice pouring a glass of water in our kitchen because he would pour the water just slightly outside the glass. He'd always hit his right shoulder in the doorway. He couldn't figure out where the center was," Lisa Green said.

But relearning to navigate the world wasn't the hardest part. Austin missed basketball. He was angry. He didn't understand why God would allow his vision of the NBA to come just into focus only to have it dissolve.

He knew everything would be hard: to trust in a bigger plan, to relearn everyday tasks but, most of all, to take a seemingly infinite number of shots to find the basket again. He could quit basketball -- everyone would understand. Or he could work harder than he'd ever had to work at anything.

"Isaiah," his mom said then, "you can make this your excuse, or you can make it your story."

By his sophomore year of high school, he was back on the court. He didn't want anyone to make excuses for him, so he kept his blindness mostly a secret. No one -- save for a few close teammates and position coaches -- knew he was playing without the use of his right eye. He wore a special prosthetic, like a thick contact lens, over the damaged eye, and no one thought much else about it. Perhaps because of that, the recruiting interest picked up right where it left off.

"It was hard for me to shoot. Even to this day, after I lost vision in my eye, I have no depth perception," Austin said. "So I can't really tell how far people are away from me, or how far the basket is away from me. So all of my shooting is 100 percent muscle memory."

On new courts, Austin would take hundreds of reps until he found the basket, and then even more until he could feel where his body needed to be on every shot. He studied the plays of every position in order to know where teammates would be when he caught the ball on the block. He learned to drive left, to do his pull-up jumpers going left.

During his senior year in 2013, Austin was ranked as the No. 3 prep player in the country behind Nerlens Noel and Shabazz Muhammad. Austin led Grace Preparatory Academy to back-to-back state titles and was a McDonald's All American.

College scouts outnumbered parents at games, none of them privy to Austin's blindness. But something else remained unknown, even to Austin. His retina tear was potentially not a freak accident. It was also not the thing that would once again rip away his chance to play in an NBA jersey. It was, however, most likely a symptom of what would.

As an eighth-grader, Austin, now 25 years old, suffered an injury that almost took him away from basketball forever. "Isaiah," his mom, Lisa Green, said then, "you can make this your excuse, or you can make it your story." Tom Pennington/Getty Images

OF ALL THE offer letters in the mailbox, Austin decided to accept the one from Baylor. It was close to home, and he would be the highest-ranked high school player the university had ever signed. Head coach Scott Drew became aware of Austin's blindness during his senior year in high school, but it didn't affect his commitment.

"Normally with vision, someone might struggle with their depth, and their shooting, and Isaiah was shooting NBA 3s, so that wasn't a problem either," Drew said. "As well as he played with one eye, you would have never thought that he only had one eye."

Austin started every game as a freshman and led the Big 12 in blocks his freshman and sophomore years. By January 2014, Austin's sophomore year, the Bears were in March Madness contention, and Austin was playing with a skill set unheard of for a guy his size. He knew it would be his time to declare after that season. But first, he had to come clean about his disability. After practice one day, Drew let him speak to the team. Only a few close teammates had known, so to the rest, out tumbled everything Austin had never told them in two years of playing together -- the surgeries, the frustration and the pain.

He also went public with his story. Thousands of emails came in thanking him and sharing personal stories, all while Austin helped lead the Bears to the Sweet 16.

Ahead of the draft, predictions were all over the map. His disability was a factor to some experts, negligible to others. In some discussions, he was to be selected in the first round. Others had him going undrafted completely. Austin didn't pay much mind to the chatter.

"I thought my dream was going to come true. I thought that on June, what was it, 26th, I was going to hear my named called, and I was going to walk across the stage and put on a team hat," he said.

The 2014 NBA draft didn't go exactly how Austin had imagined. But he still had the support of his family, including his mom. Courtesy Lisa Green

DRAFT PROSPECTS GO through medical testing on the second day of the NBA combine. There is a stop at every team doctor, each with questions and tests of their own. The first doctor of the day examined Austin closely: He noted how, despite his being 7-foot-1, Austin's arms, legs and fingers were disproportionately long. He saw the way Austin's breastbone curved outward, the way his joints seemed loose and flexible. These could, of course, just be the markers of someone who, from childhood, fell far enough outside the bell curve of height averages to be off the chart entirely.

"Have you ever heard of Marfan syndrome?" the doctor asked.

Austin had not. He soon learned it was a connective tissue disorder that most often affected the heart and eyes. He had been tested once, as a child, but it had come back negative, and Austin had no memory of it.

Blood was drawn, sent out to labs, centrifuged and analyzed. All the while, Austin continued to work out for various teams, several of which told him they'd like to select him in the first round.

The way Austin saw it, he'd paid his dues. He'd already been through the experience that was meant to humble him, to give him purpose, to make him work harder. Surely there couldn't be another hurdle -- but that day in June 2014 he pulled onto his street and saw everyone's cars, he learned there would be. He would have to make a choice between risking his life on the basketball court or giving up his dream entirely.

THE DOCTOR CALLED Austin's mother with the results: He had tested positive for Marfan syndrome. She gathered the people closest to Austin that June day to break the news to him together. She was afraid of what he might do if he were alone.

The advice given by the team of NBA physicians and by the Marfan Foundation guidelines was that Austin should never play basketball again. The NBA ruled him ineligible. The risk was too great; his aorta could rupture with the strain of competitive play. In the worst-case scenario, he could die on the court.

Marfan syndrome affects one in every 5,000 people. It is typically genetic, but in around 20% of cases, as in Austin's, it's caused by a spontaneous genetic mutation. It is important to keep one's blood pressure and heart rate low and avoid any high-impact activities. It most often affects the eyes -- including a significantly increased risk of retinal detachment -- as well as blood vessels and the heart.

"Basketball taught me how to interact with people. Basketball taught me how to be a good friend and to be a good teammate. It taught me how to not hang my head too low from a loss, and it taught me not to hold my head too high from a win," Austin said. "So it was like I was losing one of the closest family members in my family at the time, like suddenly, and I had no control over it."

Silver extended an invitation for Austin and his family to come to Brooklyn, New York, for the draft; the NBA wanted to do something that night to honor him. Austin didn't know exactly what to expect, but he packed his best suit and left for New York just as he would have if the previous five days had never happened.

There in the green room, just after the Atlanta Hawks selected Adreian Payne with the 15th pick, the mood grew somber as Silver leaned into the microphone and explained why Austin would remain undrafted. When he was finished, he invited Austin on stage as a ceremonial pick.

"With the next pick in the NBA draft, the NBA selects," Silver said, "Isaiah Austin."

Austin wiped his eyes just before shaking Silver's hand. He smiled for the photo, but just after the final camera flashed, he dipped his head, the corners of his mouth turning down as the tears caught in his throat.

For every other player that night, the questions from the media were about a new team, a specific city, how they would make an impact in the season to come. They were laced with excitement, confidence, hope. Austin's questions were too general: What comes next? How will you recover from this? They were asked delicately, in hushed voices that had a lilt of sympathy -- the one thing Austin never wanted.

"The depression," Austin said, "it just swallowed me immediately. I tried so hard to get out of it. I tried to put on a smile and tell people I was OK, but then once the cameras turned off, I was just, I was dead but I was alive. It's my darkest days for sure. I really can't tell you why I didn't commit suicide. But I could tell you for at least a year of my life, I thought about it every night."

Austin went home to Dallas, enrolled once again in classes at Baylor, joined the team he had just left as a member of the coaching staff, tried to build a life without basketball as the sun around which he orbited.

"He was doing things at times that were reckless," said Dwon Clifton, Austin's agent. "It almost seemed like he was just trying to see how fast he could go without crashing. The places he would go, the type of people he started to hang out with. He made a lot of decisions that were ill advised from me, from his mom."

Austin did not touch a basketball for a year and a half. Doctor after doctor emphasized what the NBA had said: Not playing basketball was the right decision. The risk was too great. He could die.

Austin went to a Marfan Foundation conference in the summer of 2014. He needed to find a way back to playing basketball -- and learning more about the disease and meeting people in the community could possibly lead him there. He met Dr. David Liang, a specialist in the disorder based at Stanford, who agreed to examine Austin in California and assess the risk.

Their first step was an echocardiogram. Since the biggest risk factor for people with Marfan is an enlarged aorta, Liang wanted to measure and monitor Austin's carefully. His aorta was 1 millimeter above the normal range.

Liang thought Austin's quality of life was worth considering, too. What was his life without the one thing that made him who he was? Was the depression a bigger risk to him than Marfan? Liang cleared Austin to begin some light scrimmaging at Baylor, to play in a rec league, with the promise Austin would come back to Stanford every six months for another echocardiogram. Austin was not to lift heavy weights, as it can cause a spike in blood pressure.

Despite Liang's advice to take it easy in rec league, Austin didn't have the capability. He said he felt great, never was short of breath or experienced chest pains. He had something to prove to himself, to God, to the NBA: He could do this.

After some time and careful consideration, Liang medically cleared Austin to play professional basketball in November 2016.

"I think there is risk. There's no way around that," Liang recalled of his conversation at the time with Austin. "There are risks associated with playing, OK? What do I think that risk is? I don't think it's super high. And so can I say that you're risk-free? The answer's no. Can I say that the risk could possibly be in the range of what's reasonable? And the answer is yes."

Together, they made their case to the NBA. Liang wrote a letter stating the level of risk associated with Austin playing basketball is within reason. They met with an NBA cardiologist in New York, but he remained unconvinced. Teams at home and abroad were calling Austin's agent, expressing their interest after hearing he might be available, but for the NBA, it was too much of a risk. The league turned him down. The news felt like another blow for Austin.

There was one team, though, that remained interested.

For the 2018-19 season, Austin averaged 35 points and more than 10 rebounds per game for the Nanjing Monkey King in the Chinese Basketball Association. VCG/VCG/Getty Images

ISAIAH AUSTIN HAD never been so happy to go to practice. He had signed his first professional contract, with Serbian club FMP. He had also signed a waiver exempting FMP and the Adriatic Basketball Association from liability should Austin be injured or die during play.

Austin had never lived alone, he knew no one in the area, he didn't understand the street signs, the food was all new, the money he was making was a far cry from the millions of the NBA, but it didn't matter. He was starting to feel like himself again. The depression was lifting.

"It was almost like watching someone save his life, literally, because I can tell you right now he was working past it, that dark moment, but to say I could see into the future that he would continue to stay that strong without basketball, I can't say," said Clifton, who helped Austin secure his overseas contract.

The motivation to succeed was high. Austin's girlfriend, Alexa, was pregnant. She soon joined him in Serbia, where their son, Zeke, was born in May 2017. Alexa and Zeke returned to the U.S., though, and they were all left to endure time apart.

"I knew that if I wasn't feeling right, then I wouldn't have went back to basketball. I wouldn't have. Even if I wasn't happy," Austin said. "Because the last thing I would want is to have one of my family members see me die on the court."

Austin believes there is zero risk in playing basketball. Alexa agrees, as do his mom and stepdad. To them, the same risk we all take by entering the world every day is what Austin faces on the court -- no more, no less. That doesn't mean they -- and Liang -- don't worry, though.

"Well, I worry that he's going to tear his aorta and that he'll die," Liang said. "Or somebody will hit him in the eye and he'll have another retinal detachment and lose the other eye. I think those are things I worry about. And every once in a while, I'll ping Isaiah and say, 'How you doing? Get your butt in here for your echo.' Because I worry about him still."

After two seasons in Europe averaging just below 10 points a game with restricted playing time as a foreign player, Austin eventually signed with the Guangxi Rhino in the Chinese National Basketball League in June 2018, then quickly moved up to the Chinese Basketball Association in October. He immediately dominated with the Nanjing Monkey Kings. He ran the pick-and-roll, led the team in blocks, stretched the floor and shot with an easy gracefulness, all while playing against NBA-level talent including Stephon Marbury, Jimmer Fredette and Michael Beasley.

But when the games ended, the loneliness set in. He couldn't rock Zeke to sleep, kiss Alexa good night. He was 8,000 miles away, in an area of China where next to no English was spoken. He missed home, but ultimately, he decided the sacrifice was worth it to be living his dream of playing pro ball -- even if it wasn't in the NBA.

Austin ended up averaging 35 points and more than 10 rebounds per game in China. But what happens when you dedicate your life to something that does not, cannot, reciprocate in the way you'd expected? When what you love the most becomes full of risk and sacrifice? Is it possible to feel fulfilled by a loophole, especially when opposing players and coaches all over China ask the same question: "Why aren't you playing in the NBA?"

Austin has yet to sign with a team for 2019-20, but wherever he ends up, his son, Zeke, and his girlfriend, Alexa, will go with him. Bill Roach for ESPN

BACK IN DALLAS, Austin, now 25, makes his son a grilled cheese sandwich as Zeke crashes his toy cars into each other. The season in China ended nearly two weeks prior, and for so many reasons, it's good to be home. Zeke will soon be old enough to be tested for Marfan. Liang says the odds are about 50-50, but Isaiah and Alexa say they don't believe he has it.

It's been five years since Silver called Austin's name from the podium, and instead of observing the date like the anniversary of a death, it's just another day now. Austin thinks he will remain in Asia next season, perhaps in Japan or Korea, and Alexa and Zeke will be able to join him this time. He will continue to monitor his heart through regular checkups.

A commercial comes on TV for the NBA playoffs. Austin doesn't seem to notice, but when the topic comes up later, he lays out his predictions for the postseason with the excitement of a longtime fan. At the end, though, he grows wistful about his dream to play in the NBA.

"I still have a little bit of a problem letting it go, but I just know that's better for me personally. It was better for my health, my mental health, not to be stressing on something that's just completely out of my control," Austin said of the NBA's decision.

"I have to focus on the now, and I have to be thankful that I'm even playing again."

-- Additional reporting by E:60 features producer Max Brodsky