RT Book, Section A1 Kanungo, Shibani A1 Steiner, Robert D. A2 Kline, Mark W. SR Print(0) ID 1182929807 T1 Disorders of Cholesterol Synthesis T2 Rudolph's Pediatrics, 23e YR 2018 FD 2018 PB McGraw-Hill Education PP New York, NY SN 9781259588594 LK accesspediatrics.mhmedical.com/content.aspx?aid=1182929807 RD 2024/03/29 AB Cholesterol is an essential lipid, available through diet but also synthesized endogenously from acetyl-coenzyme A, formed as a byproduct of glucose and fatty acids through glycolysis and β-oxidation pathways, respectively. Cholesterol is a major end product of the isoprenoid and sterol biosynthetic pathway involving numerous enzymatic steps. Enzymatic defects in the pre-squalene cholesterol synthesis pathway are responsible for inherited sterol disorders such as mevalonic aciduria (MVA) and hyper-immunoglobulinemia D and periodic fever syndrome (HIDS). In the descending post-squalene pathway, enzymatic defects are responsible for disorders such as Antley-Bixler syndrome with genital anomalies and disordered steroidogenesis (ABS1), congenital hemidysplasia with ichthyosiform nevus and limb defects (CHILD) syndrome, CK syndrome, sterol C4 methyl oxidase deficiency (SC4MOL), X-linked dominant chondrodysplasia punctata 2 (CDPX2)/Conradi-Hünermann syndrome, lathosterolosis, desmosterolosis, and the widely known Smith-Lemli-Opitz syndrome (SLOS). Hydrops-ectopic calcification–moth-eaten (HEM)/Greenberg skeletal dysplasia was earlier thought to be a disorder of sterol metabolism but more recently has been shown to be a laminopathy.