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Congenital adrenal hyperplasia and P450 oxidoreductase deficiency
Author(s) -
Krone Nils,
Dhir Vivek,
Ivison Hannah E.,
Arlt Wiebke
Publication year - 2007
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1111/j.1365-2265.2006.02740.x
Subject(s) - congenital adrenal hyperplasia , endocrinology , virilization , medicine , steroid biosynthesis , 21 hydroxylase , phenotype , oxidoreductase , androgen excess , biology , ambiguous genitalia , hydroxysteroid , steroid 11 beta hydroxylase , androgen , adrenal gland , enzyme , steroid , dehydrogenase , genetics , gene , hormone , biochemistry , insulin resistance , polycystic ovary , insulin
Summary Congenital adrenal hyperplasia (CAH) comprises a group of autosomal recessive disorders, which are usually due to inactivating mutations in single enzymes involved in adrenal steroid biosynthesis. The characteristics of the biochemical and clinical phenotype depend on the specific enzymatic defect. In 21‐hydroxylase and 11β‐hydroxylase deficiency only adrenal steroidogenesis is affected, whereas a defect in 3β‐hydroxysteroid dehydrogenase or 17α‐hydroxylase also involves gonadal steroid biosynthesis. Recently, mutations in the electron donor enzyme P450 oxidoreductase were identified as the cause of CAH with apparent combined 17α‐hydroxylase and 21‐hydroxylase deficiency, thereby illustrating the impact of redox regulation enzymes on steroidogenesis. P450 oxidoreductase deficiency (ORD) has a complex phenotype including two unique features not observed in any other CAH variant, skeletal malformations and severe genital ambiguity in both sexes. Despite invariably low circulating androgens, females with ORD may present with virilized genitalia and mothers may suffer from virilization during pregnancy. This apparently contradictory finding may be explained by the existence of an alternative pathway in human androgen biosynthesis, with important implications for physiology and pathophysiology. This review discusses the biochemical and clinical presentation and the genetic and functional basis of the currently known CAH variants, with a specific focus on ORD.