TOPBP1 and pulmonary arterial hypertension: Genomic primer pairs were designed to amplify all of the coding regions and the intron-exon boundaries of known PAH-associated genes including BMPR2 [NM_001204.6], ACVRL1 [NM_001077401.1], ENG [NM_001114753.2], SMAD8 [NM_005905.5], SMAD4 [NM_005359.5], CAV1 [NM_001753.4], BMP9/GDF2 [NM_0016204.1], KCNK3 [NM_002246.2], KCNA5 [NM_002234.3], EIF2AK4 [NM_001013703.3], TOPBP1 [NM_007027.3], NOTCH1 [NM_017617.3], and NOTCH3 [NM_000435.2].