Deaf BSL family with ASD young child

Hello everyone! 

I've recently been approached by a BSL worker and teacher of the deaf, who works with a family where all members are deaf and using British sign language. their son (aged 3) has just received a diagnosis of high functioning autism. Although they are fully involved within the deaf community they feel isolated in that they are the only BSL family with an autistic child that they know of. Does anyone have any experience of working with such families , especially on keeping a deaf ASD child safe when out and about. Any advice very welcome. Any contacts with other such families very welcome!