A variant in the fibronectin (FN1) gene, rs1250229-T, is associated with decreased risk of coronary artery disease in familial hypercholesterolaemia

•Fibronectin, encoded by FN1, is a key component of atherosclerotic plaques.•An FN1 variant, rs1250229-T, is associated with higher cardiovascular (CV) risk.•We found lower risk with rs1250229-T in familial hypercholesterolaemia.•Any mechanistic basis for this discrepancy is speculative.•Our findings are hypothesis-generating and require confirmation in other cohorts.