Shared genetic variants contributed to the causality, where rs10490770 in LZTFL1 suggested direct causality (SNPs → COVID-19 → CHD), and SNPs in ABO (rs579459, rs495828), ILRUN (rs2744961), and CACFD1(rs4962153, rs3094379) may simultaneously influence their risks. The gene discussed is ABO; the disease is COVID-19.