Congenital adrenal insufficiency with 46, XY sex reversal OR 46,XY disorder of sex development-adrenal insufficiency due to CYP11A1 deficiency (MONDO_0013400) is a rare, genetic, developmental defect during embryogenesis disorder characterized by severe, early-onset, salt-wasting adrenal insufficiency and ambiguous/female external genitalia (irrespective of chromosomal sex) due to mutations in the <i>CYP11A1</i> gene. Milder cases may present delayed onset of adrenal gland dysfunction and genitalia phenotype may range from normal male to female in individuals with 46,XY karyotype. Imaging studies reveal hypoplastic/absent adrenal glands and biochemical findings include low serum cortisol, mineralocorticoids, androgens, and sodium, with elevated potassium levels. Also known as: XY sex reversal-adrenal failure, XY sex reversal-adrenal failure syndrome, adrenal insufficiency, congenital, with 46,XY SEX reversal, partial or complete, adrenal insufficiency, congenital, with 46XY sex reversal, partial or complete, cholesterol side-chain cleavage deficiency, p450scc deficiency.