Jack Osbourne revealed in a recent interview that he has been diagnosed with multiple sclerosis.
The 26-year-old son of rocker Ozzy Osbourne and Sharon Osbourne told People magazine he learned his diagnosis two weeks after welcoming his daughter Pearl Clementine with fiancee Lisa Stelly in April.
"I was just angry and frustrated and kept thinking, 'Why now?'" Osbourne told the magazine. "I've got a family and that's what's supposed to be the most important thing."
His older sister Kelly Osbourne Tweeted support to her brother on June 17. "Please support my brother @mrjacko in not only his bravery but honesty," Kelly Osbourne wrote to her followers. "I love you so much jack & I'm so proud of you!"
Jack Osbourne did not mention his diagnosis on Twitter, instead writing about his first Father's Day, "This is the best fathers days I've ever had!"
Multiple sclerosis is a disease which attacks the central nervous system, which is made up of the brain, spinal cord and optic nerves, according to the National Multiple Sclerosis Society. The progression of the disease varies from person to person and symptoms can range from mild numbness in the limbs to paralysis.
Celebrities who have been diagnosed with the disease include comedian Richard Pryor, former mouseketeer and actress Annette Funicello, talk show host Montel Williams and actress Teri Garr.
Jack Osbourne and his family starred in the MTV reality series "The Osbournes," which ran between 2002 and 2005 and depicted the family's wacky home life, as well as frequent squabbles between the Osbourne siblings.
Ozzy and Sharon Osbourne are also parents to a 29-year-old daughter, Aimee, who did not appear on the show.
Jack Osbourne's new bundle of joy is the first grandchild for Sharon Osbourne. Her husband and his first wife, Thelma Riley, have a daughter and son together and they have two children each.