There was an emotional surprise for Karen Weiner during the address of guest speaker Warwick Davis at the Langdon dinner.

“The prognosis was I wouldn’t live beyond my teenage years,” the actor and writer told the 550 guests at the Marriott Grosvenor Square in London’s West End. “My parents did a terrific job.”

Having talked about his involvement in the Star Wars and Harry Potter movies — “what a great journey” — he praised the efforts of Langdon in helping the learning disabled to lead independent lives. “You have my utmost respect and admiration.”

He cited the example of a friend who employed a Langdon member, Ben, in his company and the positive impact it had made on the workplace environment.

Ben, 27, is Ms Weiner’s son and she was visibly moved by the unexpected namecheck.

She told the JC he had been involved in Langdon since the age of 16 in Manchester and London. The job was in the warehouse of a Harry Potter merchandising business and her son loved his work, the friends he had made through Langdon and supporting Arsenal at home and away games.

“It’s given him an independent life away from family and self-confidence.”

There were similar stories from other parents at the dinner, which Langdon members had been instrumental in arranging, from choosing the invitation cards to the menu selections.

Recalling the childhood of her son — Matthew Rose, 39 — Michelle Shine said: “If he did something wrong, you couldn’t tell him off. If you told him he wouldn’t get dinner, he’d say: ‘I won’t eat for a week’. And he wouldn’t. It was very difficult.”

He was equally rebellious at school — “I don’t think he ever produced homework or took notice in class. But he reads, writes and is knowledgeable. He had a job as a computer technician.”

Taking up the story, her son said he had been volunteering with the All Aboard charity shops when he saw Langdon mentioned on the All Aboard website. He now works as a volunteer for New Chapters, Langdon’s second-hand books business.

Joining the Langdon family had “given me my independence, a sense of freedom. I have more friends than I had before. I think the future is promising.”

Ms Shine added: “He has a proper life now, not a shadow life. I’d love him to have paid employment so he can feel better about himself. But Langdon has done that for him anyway.”

Suzanne Broch said the charity had transformed the life of her son William, 28, who fulfils caretaking duties at Mill Hill Synagogue and also works at an Edgware nursery.

“He sometimes says to me: ‘I’ve got a payslip’. As much as he can be, he’s independent.

“I never dreamt he would do anything on his own. I wake every morning and thank God for Langdon.”

Racquelle Bluestone is the mother of Robert, 20, who featured in the appeal film.

“Before he started Langdon he desperately wanted friends,” she explained. “He was home schooled from the age of seven.”

Although he still lives with his family, they see a lot less of him as he holds down a part-time job and goes to the pub with his Langdon friends.

“He’ll probably go into Langdon accommodation. He’s determined to get a full-time job. He loves to do things with computers and Langdon encourage that.

“They just believe in him and he knows it.

“Knowing Robert is secure and happy also means we can think about the future — and holidays and other things people take for granted.”

The dinner raised £650,000, 30 per cent up on last year, as supporters responded to pleas to increase their donations.

It featured Langdon’s Ben Brahams as toastmaster and a performance from the Langdon choir. Members also introduced elements of the programme.

Other speakers included Nigel Henry, Langdon’s new chairman, succeeding Jonathan Joseph, to whom he paid tribute. “I’ve taken over from one of the complete pros in the Jewish charity world.”

Mr Henry is not a Langdon parent. He became involved after attending one of its dinners and coming away so impressed by members’ stories that he offered his services.

He said the charity’s successful employment and social programmes enabled those it supported to declare: “I am the best me”.

But he cautioned that the Jewish community was “only scratching the surface” in helping those with learning disabilities.