Bob Saget Died on What Would Have Been His Late Sister's 75th Birthday

Hours before news of his death broke on Jan. 9, Bob Saget paid tribute to one of the most important people in his life: his late sister, Gay.

As it turns out, Jan. 9 would have been his older sister's 75th birthday, but the former school teacher from Philadelphia died in 1994 following her scleroderma diagnosis. Saget, who was already involved with the Scleroderma Research Foundation (SRF) before his sister knew she had the disease, made it one of his "life's missions" to raise money and research for the foundation after Gay's passing.

In an Instagram post shared by the SRF early on Jan. 9, Saget wrote, "Today would have been my sister Gay's 75th birthday. She lost her life to scleroderma when she was 47. My heart goes out to all who have lost a loved one to this disease. No one should have to suffer as Gay did, which is why I'm committed to finding a cure and a proud board member of the Scleroderma Research Foundation."

Speaking to PEOPLE by email, SRF Executive Director Joanne Gold said though the organization's members were "shocked and heartbroken" by Saget's passing, "We can only hope that Bob has joined [Gay] somewhere for a long-awaited celebration together."

"Bob was deeply dedicated to our mission to find a cure for this complex disease," Gold continued. "But more than that, Bob was an uncommonly kind, generous and caring person. I can't express how deeply all of us at the SRF will miss him."

Saget got involved with the organization after founder Sharon Monsky asked the actor to host an early version of the foundation's Cool Comedy, Hot Cuisine fundraiser. Once Gay was diagnosed with the rare condition, Saget dedicated himself to fundraising, hosting the event through 2021, and sitting on the board of the SRF.

In 1996 he produced For Hope, a made-for-TV movie about the disease, loosely based on his sister's life, with Dana Delany in the lead role. The SRF has made it available to stream.

Saget, 65, was found dead on Jan. 9 in his hotel room at the Ritz-Carlton in Orlando following a performance outside of Jacksonville, Florida. He leaves behind wife Kelly Rizzo and three adult daughters from his previous marriage to Sherri Kramer.

The actor had another sister, Andrea, who tragically died of a brain aneurysm in 1985.

To donate to the Scleroderma Research Foundation in Saget's memory, click here.