PCSK9 and familial hyperaldosteronism: FH is caused by a mutation affecting apolipoprotein B [5], proprotein convertase subtilisin kexin type 9 (PCSK9; an enzyme involved in LDL receptor degradation) [6], or, most commonly, the LDL receptor gene, resulting in defective LDL receptors and/or a diminished number of LDL receptors [7, 8].