Inclusion Criteria for Delayed Puberty Children who have late (delayed) puberty may participate in this study. Children must be between 12 and 17 years of age and be healthy with the exception of having late puberty. In order to have late puberty, boys and girls should have short stature compared to their family with at least one year delay in bone age as determined by bone age x-ray and/or have the onset of secondary sexual characteristics (breast and pubic hair growth) at 12 years of age or later for a girl or 13 years of age or later for a boy.