HMGCR and familial hypercholesterolemia: Such a discrepancy between the effect size of an associated SNP and the therapeutic potential of targeting the underlying biology has already been observed in cardiovascular medicine, where genetic variants in HMGCR are associated with very modest changes in serum levels of low‐density lipoprotein (∼5% 32), but the protein product of this gene, hydroxymethylglutaryl‐coenzyme A reductase, is the pharmacologic target of the most effective drug treatment for hypercholesterolemia (statins) 33.