A consortium of investigators, institutions, and patient support groups will constitute a Rare Disease Clinical Research Network focused on a diverse group of disorders characterized by defects in steroidogenesis. We will study the longitudinal history of these rare disorders and determine the outcome of treatment on height, fertility and gender. Long-standing informal collaboration between investigators at Weill Medical College, Rockefeller University, Columbia University, the University of Texas Southwestern Medical Center, the University of Quebec, Hospital Debrosses (Lyons), and the Hospital das Clinicas da FMUSP (Sao Paulo) will facilitate the creation of a productive cooperative research network that draws on the extensive experience of each investigator. Clinical Research Centers at Weill, Rockefeller, and the University of Texas Southwestern Medical Center will participate. Each investigator in the consortium has followed a large group of patients with a specific genetic defect affecting steroid synthesis over many years, encompassing the natural history of these diseases from prenatal life to death. Creation of a storage and management database will constitute a scaffold for ongoing research, enabling the preservation and use of this large body of clinical data assembled by experts in each disorder. Moreover, design of templates for a standardized clinical description of these disorders will permit prospective studies which can offer open enrollment to affected individuals or individuals at risk. Our research group includes the investigators who have identified the molecular genetic defect for each disorder, where known, and who maintain laboratories dedicated to the identification of new mutations. The combination of clinical and molecular genetic information will raise the standard of medical care and may permit development of novel treatments based on detailed knowledge of the natural history and molecular genetic basis of these disorders. Important elements of our plan are (1) to establish the clinical research network which pools data from our sites in cooperation with the DTCC and analyzes this data, (2) to educate young investigators in the management and clinical research of steroid disorders, and (3) to strengthen our connections with patient support groups to enable individuals affected or at risk to have new kinds of input and access to optimal medical care.