Smith–Lemli–Opitz Syndrome (SLOS) is caused by an inherited, autosomal recessive genetic defect targeting the final step in the cholesterol (CHOL) synthesis pathway, specifically affecting the gene encoding the enzyme 7-dehydrocholesterol reductase [DHCR7; EC 1.3.1.21], which catalyzes this biochemical step [1,2,3]. Here, DHCR7 is linked to Smith-Lemli-Opitz syndrome.