MSI_000003995

7-dehydrodesmosterol, also known as cholesta-5,7,24-trien-3beta-ol or 24-dehydroprovitamin d3, belongs to cholesterols and derivatives class of compounds. Those are compounds containing a 3-hydroxylated cholestane core. Thus, 7-dehydrodesmosterol is considered to be a sterol lipid molecule. 7-dehydrodesmosterol is practically insoluble (in water) and an extremely weak acidic compound (based on its pKa). 7-dehydrodesmosterol can be found in a number of food items such as nectarine, orange bell pepper, cinnamon, and carrot, which makes 7-dehydrodesmosterol a potential biomarker for the consumption of these food products. In humans, 7-dehydrodesmosterol is involved in several metabolic pathways, some of which include atorvastatin action pathway, simvastatin action pathway, pamidronate action pathway, and steroid biosynthesis. 7-dehydrodesmosterol is also involved in several metabolic disorders, some of which include mevalonic aciduria, wolman disease, chondrodysplasia punctata II, X linked dominant (CDPX2), and hyper-igd syndrome. 7-Dehydrodesmosterol is a sterol intermediate in the biosynthesis of steroids. 7-Dehydrodesmosterol is a substrate of the enzyme 24-dehydrocholesterol reductase (EC:1.3.1.72), an important enzyme in the biosynthesis of Cholesterol. Cholesterol is synthesized from either Lathosterol, 7-Dehydrocholesterol, Desmosterol or Cholestenol by the enzyme 3beta-hydroxysterol delta7 reductase (EC 1.3.1.21, Dhcr7). The Smith-Lemli-Opitz syndrome (SLOS, OMIM 270400) is caused by a genetic defect in cholesterol biosynthesis; mutations in the enzyme 3beta-hydroxysterol delta7 reductase lead to a failure of cholesterol synthesis, with an accumulation of precursor sterols, such as 7-Dehydrodesmosterol. SLOS results in craniofacial, limb as well as major organ defects, including the brain. In individuals with this syndrome, mental retardation, as well as other CNS dysfunction, is almost 100\\% prevalent. (PMID: 15862627, 17197219).