Fans of Bob Saget are mourning his death this week. Joining the list of celebs and fans pouring out tributes to the "Full House" TV star and comedian is the Scleroderma Research Foundation (SRF).

Saget served on the board of the San Francisco-based organization for 25 years. The foundation paid a tribute to the actor on its website: "It is with a very heavy heart that we mourn the loss of our dear friend and Board member, Bob Saget. Bob was a champion for scleroderma patients everywhere dating back to 1991 when he first became involved with the Scleroderma Research Foundation, even before his sister Gay lost her battle with the disease."  

Saget was involved with the foundation’s fundraising event called Cool Comedy-Hot Cuisine, according to its website. In a sad twist of fate, Saget’s sister, Gay, was diagnosed with the illness while Saget was involved with the foundation. She lost her battle to the disease at the young age of 47 years old, according to multiple media reports.  

Bob Saget attends The Scleroderma Research Foundation's "Cool Comedy - Hot Cuisine" at San Francisco Palace Hotel on April 29, 2009, in San Francisco, California.

Bob Saget attends The Scleroderma Research Foundation's Cool Comedy - Hot Cuisine at San Francisco Palace Hotel on April 29, 2009, in San Francisco, California.  (Steve Jennings/WireImage)


Scleroderma means "hard skin." According to health experts, it is an autoimmune disease that causes the skin to become inflamed, which then sparks the body’s immune system to make too much collagen. Health experts told Fox News the disease varies in severity and rate of progression.   

"Scleroderma (aka systemic sclerosis) is a chronic autoimmune condition characterized by progressive thickening, tightening, and hardening of the skin," Dr. Wendy Chi, a rheumatologist for Mount Sinai Health System in New York City, told Fox News in an email and added, "It typically starts on the hands and face, but can spread to involve extremities and trunk in certain patients." 


Scleroderma  (BSIP/UIG Via Getty Images)

Chi, who is also an assistant professor of medicine in the division of rheumatology at Mount Sinai, explained to Fox News that some patients with scleroderma can develop complications involving the heart (pulmonary hypertension) and/or lungs (interstitial lung disease), which can lead to chronic shortness of breath.  

Chi also explained that the disease can affect various systems in the body. Some patients have involvement of the gastrointestinal tract (gastroesophageal reflux, dysmotility), which can cause chronic abdominal pain, bloating, diarrhea/constipation and malnutrition, the rheumatologist told Fox News. Chi also said while the kidneys are rarely involved, most patients diagnosed with scleroderma also have a condition called Raynaud's syndrome, which causes decreased circulation to the fingers in response to cold and may lead to ulcerations. 

Physical therapists told Fox News the disease can affect someone’s ability to perform simple tasks throughout the day, such as buttoning a shirt and texting on a phone when the disease affects their hands.  

Chi told Fox News, "The skin changes from scleroderma often cause restricted movement of the fingers (or other joints if more extensive). Tightening of the skin around the mouth can also make dental procedures difficult."  


Scleroderma (BSIP/UIG Via Getty Images)

Dr. Margrit Wiesendanger, a rheumatologist at Mount Sinai Health System in New York who has a dual MD-Ph.D. in the discipline of immunology, told Fox News that scleroderma is rare disease with an onset between 20 and 50 years. "Although women are affected more often than men, male patients with scleroderma have a worse prognosis in terms of skin fibrosis, pulmonary hypertension and mortality," Wiesendanger told Fox News. 

Wiesendanger said treatments are typically directed toward minimizing symptoms and some treatments involve the use of immunosuppressive medications.  


Chi added, "Unfortunately, some patients progress despite medications. For very severe cases, bone marrow transplant is sometimes considered as a treatment."   

Both experts told Fox News that there is no cure for this disease, words Bob Saget hoped to change. His efforts were noted by the Scleroderma Research Foundation, which commented on its website, "We could not have asked for a more passionate, creative, and dedicated partner in our efforts to find a cure."