I don't know, but he is the nephew of Don Bellisario, the executive producer.
no
Yes and no. Sean Murray's mom is Vivienne is Donald Bellisario's fourth wife thus making Sean to be Donald's stepson. Since Patrick is Donald's nephew and Sean is Donald's stepson, yes they are...
Colin Hanks is the son of Tom hanks, and Sean Murray is the stepson of Donald Bellisario.
bill murry and sean murry are actually not realated at all