3β-hydroxysteroid dehydrogenase type 2 deficiency (3βHSD2D) is a very rare variant of congenital adrenal hyperplasia (CAH) causing less than 0.5% of all CAH. The aim was to review the literature.
3βHSD2D is caused by HSD3B2 gene mutations and characterized by impaired steroid synthesis in the gonads and the adrenal glands and subsequent increased dehydroepiandrosterone (DHEA) concentrations. The main hormonal changes observed in patients with 3βHSD2D are elevated ratios of the Δ5-steroids over Δ4-steroids but molecular genetic testing is recommended to confirm the diagnosis. Several deleterious mutations in the HSD3B2 gene have been associated with salt-wasting (SW) crisis in the neonatal period, while missense mutations have been associated with a non-SW phenotype. Boys may have ambiguous genitalia, whereas girls present with mild or no virilization at birth. The existence of non-classic 3βHSD2D is controversial. In an acute SW crisis, the treatment includes prompt rehydration, correction of hypoglycemia, and parenteral hydrocortisone. Similar to other forms of CAH, glucocorticoid and mineralocorticoid replacement is needed for long-term management. In addition, sex hormone replacement therapy may be required if normal progress through puberty is failing. Little is known regarding possible negative long-term consequences of 3βHSD2D and its treatments, e.g., fertility, final height, osteoporosis and fractures, adrenal and testicular tumor risk, and mortality.