Are some twins conjoined due to genetic factors? IOW, do conjoined twins have a greater probability of giving birth to conjoined twins, themselves, than the greater population?
Well, conjoined twins are a type of identical twin. Identical twins happen when one fertilized egg splits into two cells, and as I understand it, that’s a completely random event, meaning that there’s no tendency towards having identical twins that can be inherited. (Women can inherit the tendency to ovulate more than one egg at a time, which leads to fraternal twins.) So I doubt that conjoined twins would have greater odds of having conjoined twins than anybody else would.