Complex sentence: He is related to the entire Beale/Fowler clan and also the entire Mitchell clan, but he has never appeared on screen, his father Grant and the paternal side of his family have never met him and do not even know of his existence.
Split into simpler sentences: He is related to the entire Beale/Fowler family and also the entire Mitchell famile, but he has never appeared on screen. His father Grant and the paternal side of his family have never met him and do not even know of his existence.