Jack Osbourne says his new motto is "adapt and overcome".

The son of Black Sabbath rocker Ozzy was recently diagnosed with the debilitating central nervous system disease Multiple Sclerosis.

The 26-year-old received the crushing news just weeks after his first child, a daughter called Pearl, was born in April.

But the reality TV star added that his initial anger has transformed into a determination to make the best of his situation.

"'Adapt and overcome' is my new motto," he told Hello! magazine. "The timing was so bad. I'd just had a baby, work was going great Then I got really sad for about two days, and after that I realised, being angry and upset is not going to do anything at this point - if anything it's only going to make it worse."

Jack's mother Sharon also spoke about her reaction when she found out about her son's illness.

She is questioning whether she is to blame for the disease, while Jack's father Ozzy mused on how unfair the diagnosis is.

"I keep thinking, What did I do wrong? What did I eat or drink when I was pregnant?' I feel like it's somehow my fault," Sharon said, with Ozzy adding, "If it was me, you'd think: Ozzy had a reputation and it caught up with him,' but Jack is such a good guy."

Jack's sister Kelly has also spoken out in support of her sibling.

The TV star took to social networking site Twitter to express her pride and love for her brother and urged fans to show their support.

"Please support my brother @mrjacko in not only his bravery but honesty! i love you so much jack & I'm so proud of you! (sic)" she wrote.