THE SOMATIC and sexual development of a person from infancy to adulthood consists in a series of transitions. The age at which certain phenomena of maturity usually make their appearance has been established for normal rates of development. However, it is recognized that considerable variation in the degree of development and time of appearance of these phenomena occurs in apparently normal persons. Occasionally, the time of appearance of certain of the manifestations of maturity may be so retarded or accelerated that the development of the person must be considered as distinctly abnormal. This report is concerned with pathological precocity, not with physiological "early" sexual development.
Discussions of the different causes of precocious development have been well presented by different authors1; therefore problems in differential diagnosis will not be considered. This report concerns the clinical and laboratory findings exhibited by two brothers with precocious sexual and somatic development. Another brother,