CBS and Dravet syndrome: Considering the functional effects of the MTR c.2756A>G (rs1805087), MTRR c.66A>G (rs1801394), TC2 c.776C>G (rs1801198), CBS c.844ins68, and MTHFD1 c.1958G>A (rs2236225) polymorphisms, it is expected that these polymorphisms may be associated with the maternal DS risk and several studies have been carried out to determine this association.