John P. Gearhart, M.D., Professor and Director of Pediatric Urology at Johns Hopkins Children's Center, has both basic science and clinical interest in the child born with major congenital birth defects including the bladder extrophy-epispadias condition, disorders of sexual development (DSD), and childhood urinary cancers. Dr. Gearhart's clinical and surgical interests are focused on the evaluation and treatment of the bladder muscle, nerve supply, and collagen content of the extrophied bladder. In addition, long-term follow up studies of patients with disorders of sexual development are currently underway. Also, new techniques to evaluate the prognosis and long-term outlook for children with childhood kidney tumors are under study. Dr. Gearhart has an academic and clinical interest in the reconstruction of the child who has undergone previous failed bladder exstrophy closures.