Although it is not fully understood why the same allele generates subtly or profoundly different phenotypes in most of the FH cases, the outcomes of the studies reporting digenic mutations LDLR/LDLRAP1, although very few, can be fundamental for (1) understanding better the phenotype–genotype correlations and (2) further elucidation of the FH heterogeneity and the mutation spectrum. This evidence concerns the gene LDLR and familial hyperaldosteronism.