At least 37 mutations in the HSD3B2 gene have been found to cause 3β-HSD deficiency. Most of these mutations change single protein building blocks (amino acids) in the 3β-HSD enzyme, which typically reduces the activity of the enzyme. Mutations that allow the production of some functional enzyme, although at reduced levels, cause the less severe, non-salt-wasting or non-classic forms of 3β-HSD deficiency. Other mutations result in the production of an abnormally short, completely nonfunctional 3β-HSD enzyme, which causes the more severe, salt-wasting form of this condition. All types of 3β-HSD deficiency interfere with the production of a variety of hormones and lead to abnormalities of sexual development and maturation.