I guess you can call each other that. But usually people who say they have 'blood' or 'DNA' don't have much to stand on. See Elizabeth Warren.
How many Gypsies do you know ?
My great-grandmother was from Romania, she was Romanian Gypsy. I had my DNA done a couple years ago and it matched what our oral family history is - 70% Romanian/Chech. (Except for a strange 11% Scandinavian, which I haven't been able to track down.)
I suppose "gypsy" can be used derogatorily - we all know the stereotypes. I guess the technical term is "Roma" people. But in my family of Romani women, it's not offensive to us. My great-grandmother was a well-known healer. i know "gypsy" is not used derogatorily in flamenco, either.
Hitler targeted the Gypsies:
https://encyclopedia.ushmm.org/content/en/article/genocide-of-european-roma-gypsies-1939-1945Because of these things, I consider myself a descendent of the Romani-Gypsies.
I don't mind if you don't want to consider me a Gypsy. Or anyone else, for that matter.
The great thing about being a Gypsy is - we don't care. We re-locate and carry on.