Mat Baynton and James Corden both appear in a new video released to raise awareness of Williams Syndrome.

In the short clip Baynton meets up with two cynical TV executives played by Samantha Spiro and Paterson Jospeh to pitch a documentary about him running a marathon to raise awareness of the condition, which is characterized by medical problems, including cardiovascular disease, developmental delays, and learning disabilities.

Baynton explains that his nephew has Williams Syndrome but the executives want to sex up the story. Can't it be the more famous James Corden's son who has it? But he doesn't, points out Baynton. They also say that running a marathon is not that impressive after the Sport Relief exploits of John Bishop and David Walliams.

In the end an exasperated Baynton leaves and later is seen at home watching television when his Wrong Mans co-star James Corden appears talking about his 'son' having Williams Syndrome.

Watch the video here.