HSD17B3 and disorder of sexual differentiation: Among the various causes of 46,XY DSD, 5α-reductase type 2 (encoded by SRD5A2) (4, 5, 6, 7, 8) or 17β-hydroxysteroid dehydrogenase type III (encoded by HSD17B3) deficiency (9, 10, 11) and alteration of steroidogenic factor 1 (SF-1; encoded by NR5A1) function (12, 13, 14, 15, 16, 17, 18, 19, 20) have been associated with virilization at puberty.