It's a long story, so I'll cut it short(ish)
Estranged from father in late teens after parent's divorced. Domestic violence in the marriage (him) and estrangement was my choice, never regretted it. The extended family on that side cut me off at that point and I never heard from any of them again (uncles, grandmother).
Very limited contact with mother. We've lived a considerable distance apart for almost twenty years. Communication limited to messages, usually started by her. Again, this is me resisting contact. Looking back as an adult, I can see that that she parentified me as a way of coping with the marriage, and there was a very unhealthy enmeshed relationship. Once I got married and had my own children, I found myself realising just what a terrible parent she had been (and continues to be). I find all contact with her now incredibly stressful and triggering.
I don't have any contact with extended family on my mother's side. Predictably, due to the nature of the marriage, my father had made sure my mother was cut off from them. My mother picked these relationships up again after the divorce and my younger sibling was included in this, but I was at uni and she seemed to forget that maybe I should be included too (I wasn't even made aware it was happening), so I never got to know any of them. Bit awkward at my grandmother's funeral when they were all there and there was a sudden realisation that I had no idea who any of them were.
Sibling - haven't seen them in close to 20 years. I send stuff for birthday/christmas but get nothing in return. No contact to speak of.
Has anyone else found themselves in the same boat? I'm trying at the moment to figure out how to cope with my mother (with the help of a therapist) but sometimes look at the total lack of family and find it a bit shocking.