DHCR7 and Smith-Lemli-Opitz syndrome: In vitro studies on fibroblasts derived from SLOS patients and a Dhcr7-deficient neuroblastoma cell line have identified the major oxysterols formed from 7-DHC oxidation as 3β,5α-dihydroxycholest-7-en-6-one (DHCEO), 4α- and 4β-hydroxy-7-DHC (4-OH-DHC), 3β,5α,9α-trihydroxycholest-7-en-6-one (THCEO), 3β,5α-dihydroxycholesta-7,9(11)-dien-6-one (DHCDO), and 7-keto-cholesta-5,8-dien-3β-ol (7-kDHC) [48,51].