The sums of genetic (blue) and experimental (orange) evidence scores are shown for genes classified as having definitive, moderate, or limited evidence of a monogenic relationship, no relationship (NR) or disputed relationship for H/IPAH, PVOD/PCH (EIF2AK4), or syndromic PAH (ACVRL1, ENG, TBX4). Dates above the bars indicate date of first report of a gene variant identified in a PAH case.