Ambiguous Genitalia Due to 3β-Hydroxysteroid Dehydrogenase Type 2 Deficiency: Clinical, Genetic, and Functional...

3β-Hydroxysteroid dehydrogenase 2 deficiency (3βHSD2D) is a rare form of congenital adrenal hyperplasia (CAH) with variable clinical presentation. We describe a 46, XY child with ambiguous genitalia and CAH without apparent adrenal insufficiency due to 2 novel heterozygous variants in the HSD3B2 gene (c.779C > T/p.Pro260Leu and c.307 + 1G > A/p.Gly103Asp,fs29X). The disease-causing effect of the novel variants was assessed by genetic and functional studies informing on positive genotype-phenotype correlation. Sex registration was female, and no gender dysphoria has been noted until the present age of 7 years, but psychological assessments have been difficult with a concomitant diagnosis of autism spectrum disorder. Virilization that already progresses prepubertally through peripheral conversion of androgen precursors by 3β-hydroxysteroid dehydrogenase 1 will pose an increasing challenge during puberty.