I know of no other autistic relatives, not even anyone I can think of who SEEMS like an aspie. There are a number of ADHD cousins and other relatives on both sides of my family, that's all. My brother is a programmer, so you'd think he might have those traits, but I don't see autism in him. My aged father has developed OCD comorbid to his dementia, but I don't see him as having been autistic etiher.
I suspect that my paternal grandmother, whom I never knew, was the aspie in the family. What I've heard of her and read in her diaries would seem to suggest it.
I don't feel lonely in my family. My mother and I get along well. We don't get bored of one another, and we don't ever really get annoyed with each other. She isn't odd herself, but she is comparatively accommodating of many kinds of oddness. I was only diagnosed as an adult, so she never considered anything to really be "wrong" with me; I was just different and a bit weird. But she reckoned that it was because I was clever, and clever people in her experience were often odd.
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When I must wait in a queue, I dance. Classified as an aspie with ADHD on 31 March 2009 at the age of 43.