Hershkovitz et al. (2008) reported 4 undervirilized males of an extended Bedouin family. One of these had been reported (Biason-Lauber et al., 1997) to carry mutations in the CYP17A1 gene (609300), encoding P450c17, causing isolated 17,20-lyase deficiency (202110). Gas chromatography-mass spectrometry (GC-MS) urinary steroid profiling and serum steroid measurements showed combined deficiencies of 17,20-lyase and 21-hydroxylase. Sequencing of exons 1 and 8 of CYP17A1 in 2 different laboratories showed no mutations. Sequencing of the POR gene showed that all 4 patients were homozygous for G539R (), which was shown by Huang et al. (2005) to retain 46% of normal 17-alpha-hydroxylase activity but only 8% of the 17,20-lyase activity of P450c17. Hershkovitz et al. (2008) conclude that POR deficiency can masquerade clinically as isolated 17,20-lyase deficiency.
At right is a selection of images that can be regarded as milestones in the development of the steroidogenesis diagram. They are given chronological numbers, with the final version given as number "5" in the results section. Image "4" availed for even easier creation of subsequent works by being a vector image , that is, an image based on a few adjustable points in space rather than millions of pixels. Therefore, subsequent derivatives can easily be edited by free vector graphics editors, in this case Inkscape . Compared to "4", the final version "5" had the following additions: