Complex sentence: Offspring of biologically related persons are subject to the possible impact of inbreeding, such as congenital birth defects, which increases with the closeness of the relationship of the biological parents (see coefficient of relationship).
Split into simpler sentences: Offspring of biologically related persons are subject to the possible impact of inbreeding. The possibility of congenital birth defects depending on the closeness of the relationship of the biological parents (see coefficient of relationship).