(Courtesy of Grayston Family)

A 10-year old California boy who was diagnosed with cystic fibrosis as an infant is defying all the odds.

Sam Grayston, 10, of Laguna Hills, Calif., bowled a 300 last Friday at the Forest Lanes Bowling Center in Lake Forest, Calif.

"The pressure started to build and I threw the ball a little weird," Sam said. "I was really nervous, but it kept going right to left and then all the pins fell."

Sam's mother, Laurie Grayston, said that Sam had part of his intestine removed and was fed through a feeding tube until he was nine months old. She was also told that Sam would never be able to sit up on his own.

"I didn't want to believe it," said Laurie. "We didn't believe he was going to be held back. We thought he was going to be normal."

Now Sam has to undergo daily treatment for his cystic fibrosis. This includes a few arduous breathing treatments every morning and night, including a treatment that requires him to wear a vest that shakes him vigorously to clear mucus from his lungs. He also has to take medicine each time he eats and has to drink constantly to avoid dehydration.

Despite what therapists and doctors predicted, Sam started to walk and has spectacular hand-eye coordination.

His father, Joe, a Los Angeles County fire captain and former professional baseball player for the Texas Rangers, taught his son how to play baseball and golf.

"He is great with almost any sport that uses a ball and a bat," Joe said. "He is such a great athlete and he has a quiet confidence about him."

"He has the most amazing swing as a lefty, in golf and baseball," Laurie said. "He was on the 10 and 11 year old baseball All-Star team as a nine year old."

According to his mother, Sam just wanted to try bowling for fun and now he can't get enough of it. He wants all of his birthday parties to be at the bowling alley. The Graystons also set him up in a Youth Bowling League and started setting him up with private lessons.

"He just took off from there," Laurie said. "I drop him off around 10 and he will play until 6 p.m. He is just focused on it; he is focused on any sport he does."

However, Sam's passion for bowling conflicted with his ability to play baseball and he had to make a decision.

Sam decided to take some time off from baseball so he could participate in his weekend bowling league. But, initially, this decision was met with some resistance from his parents.

"I had been his baseball coach for a few years and when he told me he was going to stop playing baseball and bowl instead I was like 'Um, what?'" Joe said laughingly.

But, Sam's parents said that they want him to follow his dream and do whatever he wants.

When Sam saw the last pin fall in the 10th frame he was elated.

"Happiness, lots of happiness. Most of my friends were there and everyone was watching," Sam said.

Sam said that his favorite sport is bowling and his next big goal will to bowl a 700 series over a course of three games.

"Sam is an inspiration," his mother said. "He never complains and he is always in a good mood. He is just an all around amazing boy."