MTHFR and ventricular septal defect: In this study, five variants in the ISL1: rs1017 (NG_023040.1:g.16138A > T, 3 prime UTR Variant), NFATc1: rs7240256 (NG_029226.1:g.23449 T > C, intron Variant), VEGF: rs36208048 (NG_008732.1:g.3877C > A, 5’ upstream Variant), TBX5: rs11067075 (NG_007373.1:g.51682G > T, regulatory region variant), and MTHFR: rs1801133 (NG_013351.1:g.14783C > T, coding region variant) genes are investigated in order to construct GRS in Pakistani VSD patients.