"Return of signing urged at DisneySea"

From The Japan News, 12/10/14:

At Tokyo DisneySea in Urayasu, Chiba Prefecture, an aquatic show called “The Legend of Mythica,” that was accompanied with a sign language performance came to an end in September. However, there have been growing requests for a restart of the show from hearing-impaired people.

DisneySea began introducing the special performance, in which cast members convey the story’s outline and characters’ lines through sign language, in July 2004 with the hope that people with hearing disabilities could fully enjoy the show. The performance was continued even after the show’s contents changed, and many hearing-impaired people visited DisneySea for the show from all over the nation.

The show was terminated as the theme park’s entertainment programs were set to be renewed. Though other attractions have services such as captions for narration, only the aquatic show offered the sign language performance, which enables people with hearing difficulties to enjoy the show without taking their eyes off the show itself. These visitors are requesting the sign language performance be restarted.

The Institute Real Desire for Rare Disease Supporters, an incorporated association based in Tokyo’s Shinagawa Ward, has been conducting a signature-collecting campaign and seeking supporters with a goal to collect 10,000 signatures by year-end.

“We appreciate the request as valuable input,” an employee at the public relations division of Oriental Land Co., which operates DisneySea, said. “We ended the aquatic show to expand seasonal events. We would like to consider introducing the sign language performance into another attraction.”

Question: Why is the Institute Real Desire for Rare Disease Supporters leading the campaign? Is deafness a rare disease?

Source: http://the-japan-news.com/news/article/0001775600