In the past 50 years, since the discovery of cortisone therapy as an effective treatment for congenital adrenal hyperplasia,
many advances have been made in the study and management of 21-hydroxylase deficiency. The discovery of the 21-hydroxylase
gene was followed by the discovery of the 21-hydroxylase–deficient mouse, which has provided a useful model for testing new
treatments. As our knowledge of this disease expands, new therapies are being developed and tested in both humans and animals.