Sixteen-year-old Joe Valentine has autism and was the victim of physical assault before the summer.
He spoke to ITV News' Social Affairs Editor, Penny Marshall about the "heartbreaking" prejudice he has regularly encountered, and how he deals with it.
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The 10K and half-marathon races take place almost exactly a year after Salman Abedi killed 22 in his attack at an Ariana Grande concert.
Dmitrios Pagourtzis also had several kinds of homemade explosive devices but they were not capable of detonating, county officials said.
After early mist clears, most parts of England and Wales will have another fine, warm day with plenty of sunshine.