VDR and Cowden syndrome 1: The Hardy–Weinberg equilibrium of the VDR genetic variants was evaluated in the CS group and were observed in equilibrium in FokI (rs2228570) p = 0.77; BsmI (rs1544410) p = 0.68; ApaI (rs7975232) p = 0.85; TaqI (rs731236) p = 0.35.