Introduction: 3β-Hydroxysteroid dehydrogenase (3β-HSD) deficiency and lipoid congenital adrenal hyperplasia (CAH) are rare disorders of steroidogenesis that result in impaired synthesis of all adrenal and gonadal hormones. Affected males typically present with ambiguous genitalia and concurrent mineralocorticoid and glucocorticoid deficiency. Distinguishing between these two conditions is crucial, as their management strategies differ. Case: We report a 24-year-old male, born to non-consanguineous parents, who was clinically diagnosed with 3β-HSD deficiency during infancy. He presented at day 40 of life with ambiguous genitalia, bilateral undescended testes, and generalized hyperpigmentation. His family history was significant for an elder brother with salt-losing CAH. Initial biochemical evaluation confirmed primary adrenal insufficiency and primary hypogonadism. Notably, his steroid precursors, dehydroepiandrosterone sulfate (DHEAS) and 17-hydroxyprogesterone, were suppressed. A karyotype confirmed 46,XY. In the absence of genetic testing at that time, a clinical diagnosis of 3β-HSD deficiency was made, and he was commenced on mineralocorticoid and supraphysiological glucocorticoid replacement. He underwent bilateral orchidopexy and hypospadias repair in childhood. Pubertal induction was required, followed by maintenance testosterone therapy. Upon transitioning to adult care, a review of his biochemical profile, particularly suppressed DHEAS, which is inconsistent with 3β-HSD deficiency, raised the suspicion of a more proximal defect, such as lipoid CAH. Differentiation is imperative, as lipoid CAH requires only physiological glucocorticoid replacement, whereas 3β-HSD deficiency often needs higher doses to suppress adrenocorticotropic hormone and DHEAS. To resolve this diagnostic uncertainty and guide longterm therapy, the patient was referred for genetic studies. Conclusion Differentiating 3β-HSD deficiency from lipoid CAH is important, as both have similar clinical presentation. The absence of elevated steroid precursors, particularly DHEAS, should raise suspicion of a more proximal defect. Given the different aims of glucocorticoid therapy, establishing a precise diagnosis through genetic studies is essential to guide clinical management and minimize the morbidity associated with supraphysiological corticosteroid dosing.
Pheochromocytoma ; Mutation