Familial hypercholesterolemia (FH) is characterized by high levels of low-density lipoprotein cholesterol (LDL-C) and increased risk of developing premature coronary heart disease. The prevalence of heterozygous and homozygous FH has been estimated to be 1:200 to 1:500 and 1:160,000 to 1:1,000,000, respectively. In plasma, LDL-C levels are regulated via apolipoprotein (Apo) B-mediated binding to LDL receptors (LDLR). The LDL receptor adaptor protein 1 (LDLRAP1), an intracellular scaffold, binds LDLR to clathrin, allowing expression and recycling of LDLR. Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to LDLR, promoting its degradation and preventing removal of LDL-C from the circulation. Alirocumab is a monoclonal antibody targeting PCSK9 for the treatment of patients with high LDL-C levels. The objective of this study was to analyze FH gene mutations using next-generation sequencing and assess treatment response with alirocumab in patients carrying one or more causative mutation(s) in five FH genes.