June 18, 2012 -- Jack Osborne, the former reality-TV star and son of Ozzy and Sharon Osbourne, has been diagnosed with multiple sclerosis.
Osbourne, 26, who just had his first child, Pearl Clementine, with fiancée Lisa Stelly, spoke of his anguish on learning the news about his diagnosis with the autoimmune disease in an interview with People magazine.
"I was just angry and frustrated and kept thinking, 'Why now?'" Jack told People. "I've got a family and that's what's supposed to be the most important thing."
The disease, which typically begins to affect people in young adulthood, affects the central nervous system as it attacks the brain and spinal cord. There is no known cure for multiple sclerosis and the prognosis can be difficult to predict.
People diagnosed with the disease can suffer from mild problems, including lack of muscle control or struggles with vision and balance, or serious disability, including paralysis.
Jack Osborne gained fame beginning in 2002 on the hit MTV reality series "The Osbournes," which followed the lives of heavy-metal vocalist Ozzy and Sharon Osbourne and two of their children. Jack was portrayed as a rebellious teen and frequently bickered with his sister, Kelly.
Since the show ended in 2005, he has done work as an A&R scout for Epic Records and directed and produced a documentary on his father entitled "God Bless Ozzy Osbourne."