Lifestyle Health What to Know About Scleroderma, the Autoimmune Disease Bob Saget Fought for Before His Death The Full House star, who died Sunday night at 65, worked for years to support the Scleroderma Research Foundation after his sister Gay died from the disease By Julie Mazziotta Julie Mazziotta Twitter Julie Mazziotta is the Sports Editor at PEOPLE, covering everything from the NFL to tennis to Simone Biles and Tom Brady. She was previously an Associate Editor for the Health vertical for six years, and prior to joining PEOPLE worked at Health Magazine. When not covering professional athletes, Julie spends her time as a (very) amateur athlete, training for marathons, long bike trips and hikes. People Editorial Guidelines Published on January 10, 2022 01:10 PM Share Tweet Pin Email After the news broke that beloved comedian Bob Saget died Sunday at 65, many of his friends and family encouraged fans to donate to the Scleroderma Research Foundation, a cause that was extremely close to his heart. Saget first supported the non-profit in 1991, and then became an outspoken advocate after his sister Gay was diagnosed with the rare autoimmune disease just a year later. "My sister, Gay Saget, was a school teacher near Philadelphia. She was 44 when she was diagnosed with systemic scleroderma," he told NIH Medline Plus Magazine in 2019. "She got treatment, but it was just treating her symptoms with drugs like prednisone and cortisone. She had to move to Los Angeles to live with my parents because she needed so much help. She passed away just two years later." How the Tragic Death of His Sister Pushed Bob Saget Into a Life of Charitable Work Bob Saget. Mike Coppola/Getty Scleroderma is a rare, autoimmune connective tissue and rheumatic disease that primarily causes inflammation in the skin, and can lead to inflammation in other parts of the body, according to the National Institutes of Health. The disease causes the skin to form hard, tight patches that can grow or shrink, and sometimes suddenly disappear. In mild cases, scleroderma just affects the skin. But in severe forms, called systemic scleroderma, the disease spreads through other systems in the body and "can damage your blood vessels and internal organs, such as the heart, lungs and kidneys," according to NIH. And if scleroderma spreads through the body, it affects each organ in different ways. The lungs can develop scar tissue which can make it harder to breathe. Scleroderma in the kidneys can lead to elevated blood pressure and rapid kidney failure. Scarring of heart tissue could lead to congestive heart failure. And if scleroderma reaches the digestive system, it can cause heartburn, difficulty swallowing, bloating and diarrhea. There is no direct cure for scleroderma, and instead different treatments that can target the various symptoms of the disease, such as steroid creams for the skin inflammation, blood pressure medications for any lung or kidney problems, immune suppressants and over-the-counter pain relievers. Bob Saget, Star of Full House and America's Funniest Home Videos, Dies at 65 Saget's sister was diagnosed at age 44, and died two years later, in 1994. "She needed so much help," he told NIH Medline Plus. "It is incredibly painful to have a loved one experience a condition like this. It is a very painful disease. My family is still having post-traumatic stress disorder. I don't know how my parents endured." Watching Gay's struggle with the disease pushed Saget to become a dedicated advocate for more research into a cure. Saget directed the 1996 TV movie For Hope, about a young woman with scleroderma based on Gay's experience, which helped raise awareness of the disease. He was also on the board of directors for the Scleroderma Research Foundation for more than a decade and hosted their events for 25 years, including the annual Cool Comedy, Hot Cuisine fundraiser, where his comedian friends would do standup and attendees would dine on meals from top chefs. They raised $25 million through the years for research and treatment. Bob Saget and John Stamos at the 2006 Cool Comedy, Hot Cuisine fundraiser for the Scleroderma Research Foundation. John Shearer/WireImage The organization shared a tribute to Saget on Monday. "It is with a very heavy heart that we mourn the loss of our friend and Board member, Bob Saget," they said. "Bob was a champion for scleroderma patients everywhere dating back to 1991 when he first became involved with the Scleroderma Research Foundation (SRF), even before his sister Gay lost her battle with the disease in 1994. Bob was a deeply caring father, husband, and colleague, who was unreservedly committed to the mission of the SRF." The Full House star said in a May 2021 Instagram post that it was "one of my life's missions to help find a cure for this disease." "There are new drugs specifically for scleroderma that are helping people," he told NIH Medline Plus. "But we have a long way to go to get to even more effective treatments and eventually a cure." And Saget said that when he meets people with scleroderma, "my word to them is don't give up hope, because we are making incredible progress." To donate to the Scleroderma Research Foundation in Saget's memory, click here.