Jack Osbourne, the 26-year-old son of Ozzy and Sharon Osbourne, reveals this week in People magazine that he has been diagnosed with multiple sclerosis.

Jack Osbourne arrives at the Chateau Nightclub & Gardens at the Paris Las Vegas, April 30, 2011 in Las Vegas, Nev. Osbourne has been diagnosed with multiple sclerosis. (Ethan Miller/Getty Images)

Having been diagnosed myself when I was 40, I thought 26 sounded awfully young. But it’s actually right in the ballpark, as most people diagnosed with MS are between their early 20s and their 50s, according to the National Multiple Sclerosis Society. (Yikes: It just occurred to me I'm now almost twice Osbourne's age. Ouch.)

Osbourne’s diagnosis is on the unusual side, though, in that he’s a man: MS, like other autoimmune diseases, affects about three times as many women as men. That ratio only holds, though, for the more common relapsing/remitting form of the disease, in which symptoms appear and disappear intermittently. Equal numbers of men and women are affected by the more troublesome progressive form of MS, in which symptoms continually worsen.

Rosalind Kalb, a clinical psychologist and vice president of the National MS Society’s Professional Resource Center, says, “It’s hard — and scary” to be diagnosed when you’re as young as Osbourne is. “For a young person who’s just starting out and making big decisions about work and family,” she says, “the unpredictability makes it hard, even for people with good coping skills.”

“It’s so hard for young adults,” Kalb adds. “People wait their whole childhood waiting to grow up because they think they’ll finally be in control.” A diagnosis with MS early in life can be “the very first time that myth is threatened.”

On a positive note, Tim Coetzee, chief research officer for the National MS Society, notes that people diagnosed with MS today have huge advantages over those diagnosed even 20 years ago. New criteria for diagnosing MS have meant quicker, more certain diagnoses, which allow patients to more quickly take advantage of therapies that can alter the course of their disease. And, Coetzee notes, whereas two decades ago there were no approved therapies to treat MS, “Today there are eight disease-modifying treatments to choose from and another three before the FDA” awaiting approval. That’s in addition to medications that can treat specific MS symptoms, he adds.

Still, there is no known cure for MS, in large part because its cause or causes remain unclear.

Coetzee and Kalb are careful to note that everyone’s experience with MS is different, so there’s no telling how Jack Osbourne’s case will unfold. I will be watching with interest and sending good vibes his way.