Endocrine findings in male pseudohermaphroditism

Recent discoveries in molecular biology have much clarified the regulation and function of steroid converting enzymes. Most progress has been made in the area of cytochromes, which regulate the side chain cleavage of cholesterol (P-450 SCC) and the 17 alpha-hydroxylase- and 17,20-desmolase (or 17,20-lyase) activities (P-450 17 alpha), as well as in 3 beta-hydroxysteroid dehydrogenase. Nevertheless, there are some discrepancies between fundamental knowledge and clinical experience, which are difficult to understand: why is it possible, e.g., that cases with "pure" 17 alpha-hydroxylase or 17,20-desmolase deficiency exist, when there is only one cytochrome regulating both steps? After a brief review of clinical and biochemical findings in the various defects of testosterone biosynthesis, a case is discussed which is of interest in this respect.