Differential diagnosis in patients with suspected bile acid synthesis defects

Figure 3 3β-hydroxy-Δ⁵-C₂₇-steroid dehydrogenase activity in patient fibroblasts. In control cells (C) two sterols were observed after thin layer chromatography. These compounds were identified by gas chromatography mass spectrometry as the substrate, 7α-hydroxycholesterol and product, 7α-hydroxy-4-cholesten-3-one, of 3β-hydroxy-Δ⁵-C₂₇-steroid dehydrogenase. In fibroblasts of patient MD and another patient with known 3β-hydroxy-Δ⁵-C₂₇-steroid dehydrogenase deficiency (P), little or no 7α-hydroxy-4-cholesten-3-one was formed.