Fig. 7.

Oxysterols present in plasma of SLOS patients. A: A typical chromatogram of normal-phase HPLC-MS-MS analysis of an SLOS plasma sample that was processed in the presence of d₇-7-DHC [HPLC conditions: silica 150 × 4.6 mm column (Phenomenex, Inc.); 3 μm; 1.0 ml/min; elution solvent: 10% 2-propanol in hexanes]. d₇-7-DHC was added to the samples before workup. Chromatographic fractions that have d₇:d₀ ratios comparable to the d₇:d₀ ratio of the sterol precursor (7-DHC) present in the fluid or tissue are formed from ex vivo oxidation, whereas endogenous products have d₇:d₀ ratios close to zero. B: Structures of three endogenously formed oxysterols found in SLOS plasmas. C: 7-Ketocholesterol measured in SLOS plasmas versus SLOS severity scores.