APOE and metabolic syndrome: The phenotype of FH is also affected by other genes, including ATP-binding cassette subfamily G member 5 (ABCG5), ATP-binding cassette subfamily G member 8 (ABCG8), and apolipoprotein E (APOE), which are known to be causal genes of recessive types of inherited dyslipidemia (Figure 1) [35,36].