2 x DNs on XH's side and also XH's cousin's DC have autism diagnoses (all received whilst still in primary).
DP has an ADHD diagnosis (since we got together) and both his DC have autism (diagnosed as teens).
Two of my friends (intelligent, have really looked into it, wouldn't just say it for the sake of it) think they probably have ADHD but aren't going to seek a diagnosis as don't see the point at this age.
Friend's DD has ADHD and I think friend probably does, too.
I attended some ND awareness training at work, and can see traits in various family members, though I suspect not to the extent of meeting a diagnostic threshold. But suppose that's why many people say things like "we're all on the spectrum" (which I think is really unhelpful). I do wonder if growing up around particular traits means you gravitate towards people who are similar.
I know one family member on XH's side thinks there are several other family members who likely have autism but are older and unlikely to consider it or accept it if true.
My own DD is waiting for a return appointment with a consultant. They said she doesn't have ADHD but some social communication issues have been highlighted as warranting a further conversation. We've been waiting months, though, so I don't expect much.
DD has quite a lot going in with symptoms of OCD and anxiety, but nothing seems to be bad enough (in the medical experts' opinion) for any kind of diagnosis. I see it a bit like a landscape where she has spikes in certain areas. A mountain has to be a certain height to qualify as a mountain (~ threshold for diagnosis), and DD's topography doesn't seem to include any certified mountains, but it's seriously hilly terrain with not-quite-mountain spikes all over the place. Not sure if that makes sense outside my head! I recognise that I possibly have a couple of hills that are similar to some of hers, but am otherwise a gently rolling landscape with some varying features, but only to the extent that they make me an individual, not that they cause any issues.
So quite a few people close to me. Is that because it's more prevalent than we realise or because I'm drawn to a certin type of person? Or both? Who knows?!