Shannon died Monday afternoon at Cohen Children's Medical Center in New Hyde Park, on Long Island, of acute myelogenous leukemia, a common type of leukemia among adults, but rare among children.
"She was a remarkable and talented young lady who touched the lives of those she entertained, as well as those who cared for her over the past several months," medical center said Tuesday in a statement.
Shannon, who played the young lion Nala, had received an umbilical-cord blood transplant in August. The procedure was performed as an alternative to a bone marrow transplant. Her doctor, Dr. Larry Wolfe, said that a perfect bone marrow match for Shannon could not be found.
The search for a match was especially daunting because Shannon's mother is African-American and her father is Hispanic, from the Dominican Republic. For bone marrow transplants, minorities and those of mixed ancestry have a more difficult time finding good matches because there aren't as many people from those groups signed up as potential donors. Right now, 83 percent of African-American patients who need marrow transplants don't find matches after six months of searching, according to the National Marrow Donor Program, a nonprofit organization dedicated to helping patients receive transplants.
On her website, which includes a photo of Shannon as Nala and a video of her singing "The Circle of Life," the 78-pound actress said, "Some people think that the test for compatibility is scary!
... All it really takes to get started is a cotton swab of the inside of your cheek.
"So please get tested today. Who knows? You might be my match. Or, you may be able to help other young people with similar illnesses. And remember... 'One swab will do the job."' Shannon was forced to quit the show in April. She beat out hundreds of other hopefuls last year to earn her spot playing Nala, the childhood pal and girlfriend of Simba, hero of "The Lion King." She split the role with another girl, performing four shows a week for six months.
In a hospital interview with The Associated Press after being diagnosed, the young actress talked about her love for the theater.
"It's an indescribable feeling, being on stage," she said. "I portray this character with fears, but who is so tough. I feel like that's who I am."
Her long, curly brown hair was gone because of chemotherapy, but the sixth-grader said the most difficult part was being away from acting and her friends.
Keys, Rihanna and 50 Cent campaigned to help Tavarez find a bone marrow donor, and cast members held bone marrow donor registration drives outside the play's Minskoff Theater. Katharina Harf, co-founder of the bone marrow donor center DKMS, said the donor center registered 10,000 people as potential donors. Keys skyped with Tavarez while she was at the hospital, Harf said, and the singer, Rhihanna and 50 Cent urged their fans to sign up as potential donors.
Child performers from "The Lion King" and other shows also sold bracelets and key chains that read, "Shine for Shannon," to raise money to help pay for her medical bills.
"It's rare that you meet such a spirited girl at such a young age," Harf said. "She touched so many people to register. She was really, really a special girl."
"Shannon's bright smile, amazing talent, and courage will continue to inspire us in our efforts," the New York Blood Center said in a statement.
DKMS donor registry: http://www.getswabbed.org
Shannon Tavarez: http://matchshannon.com