Wish comes true at USC for ill teenage pitcher

David Thompson’s mom, Kay, knew something was wrong when he unexpectedly suffered four fractures in a year.

Doctors soon had the reason: her son had common variable immune deficiency, a disease that makes it harder to fight off and recover from illness.

A baseball player for as long as he could remember, Thompson was faced with losing the game he loved. Then 14, he was forced to give up hitting (several of his broken bones came with the simple swing of the bat) and to wear a back brace when he pitched.

But the right-hander didn’t give up.

“That’s what he lives for is his baseball,” Kay Thompson said. “That’s just who he is.”

Now 16, Thompson not only kept playing but has managed to stay injury free of late. And while his pitching has been limited, he totaled 11 strikeouts in six innings at a recent baseball tournament.

Yet there was one thing he had always thought about -- having his throwing motion evaluated by USC pitching coach Tom House, whose instructional videos he had watched since middle school.

House is the “best pitching coach in the world,” Thompson said.

On Tuesday, that wish came true, thanks to the Make-A-Wish Foundation.

After warming up with a bullpen session at USC’s Dedeaux Field, he found himself covered in motion sensors and throwing 80-mph fastballs, curve balls and changeups -- with accuracy –- as eight cameras captured each move he made. The sensors -- on his hands, arms, head and thighs -- recorded everything from order of movement to waist rotations and balance and were later simulated on a nearby computer.

House then took that information to analyze Thompson’s delivery and offered tweaks in an otherwise solid pitching performance. One of those tweaks was to make sure Thompson’s left knee faced the shortstop at the start of his delivery.

The motion analysis also showed that Thompson is doing well.

“Whoever’s been working with him has done a great job,” House said.

Thompson comes from Florida’s Flanagan High School, a 6A state champion and the country’s No. 1 baseball team. He missed the last two months of the season and said it can be unsettling to constantly battle injuries.

“The only upsetting thing is to see guys that you’re just as good as or better than that are just great,” Thompson said. “You see all these amazing things and go, ‘Wow, I wish I was where I was or where I should have been.’”

The only flaw to show up in Thompson’s delivery was a slight lean due to back injuries he’s sustained.

Yet House doesn’t see the disease holding Thompson back.

“He’s not going to let any illness bother him, I’m telling you right now,” House said. “He’ll deal with it and move forward.”

After receiving good results from House, Thompson was asked whether his wish was worth the trip from Pembroke Pines, Fla.

“I couldn’t have thought of anything better,” Thompson said. “This is perfect.”

deantae.prince@latimes.com