Only wayside astrologers bluff on compatibility of stars and attribute ill effects to parents based on that. A horoscope is a representation of positions of nine planets in the zodiac at the time of birth at a given place and all the planets influence our life in tandem and they are not like political parties who are concerned with only the party members. So your question is meaningless. Read my blog navagrahastro.blogspot.in to get a better insight into astrology.