Primary gonadal failure.

The term primary gonadal failure encompasses not only testicular insufficiency in 46,XY males and ovarian insufficiency in 46,XX females, but also those disorders of sex development (DSD) which result in gender assignment that is at variance with the genotype and gonadal type. In boys, causes of gonadal failure include Klinefelter and other aneuploidy syndromes, bilateral cryptorchidism, testicular torsion, and forms of 46,XY DSD such as partial androgen insensitivity. Causes in girls include Turner syndrome and other aneuploidies, galactosemia, and autoimmune ovarian failure. Iatrogenic causes in both boys and girls include the late effects of childhood cancer treatment, total body irradiation prior to bone marrow transplantation, and iron overload in transfusion-dependent thalassaemia. In this paper, a brief description of the physiology of testicular and ovarian development is followed by a section on the causes and practical management of gonadal impairment in boys and girls. Protocols for pubertal induction and post-pubertal hormone replacement - intramuscular, oral and transdermal testosterone in boys; oral and transdermal oestrogen in girls - are then given. Finally, current and future strategies for assisted conception and fertility preservation are discussed.