Deficiencia de 3β-hidroxiesteroide deshidrogenasa: una causa rara de hiperplasia adrenal congénita

The congenital adrenal hyperplasia corresponds to a group of inherited diseases with enzyme defects that alter the cortisol biosynthesis. The 3β-hydroxysteroid dehydrogenase type 2 deficiency is a rare cause of this defect, where the male genital development is altered but little virilization in affected women is present. In humans two isoenzymes have been described, type I and type II, coded by HSD3B2 and HSD3B1 genes, respectively, and with specific tissue distribution. The screening programs to congenital adrenal hyperplasia report paradoxical elevation of 17-hydroxyprogesterone secondary to peripheral effect of 3β-hydroxysteroid dehydrogenase type 1, an isoenzyme of 3β-hydroxysteroid dehydrogenase type 2. Type 1 has a lower Michaelis constant with the substrate; additional condition that relates with the paradoxical effect of the 17-hydroxyprogesterone. Besides the low prevalence, the study of this defect has had important progress about molecular information and hormonal diagnosis, data that has been confirmed with the identification of genetic alteration in the described gene, reducing the possibility of overdiagnosis; an event that was showing frequently with the initially cut-point stablished especially for milder forms of the disease.