Turners Syndrome is a genetic condition in females that is a result of abnormal chromosomes. Patients with Turner syndrome are typically short, have abnormal physical features, and lack the physical changes normally associated with puberty. In addition, some patients with Turner syndrome have low bone density (osteoporosis) and differences in learning abilities.

This study will research the effects of steroid hormones on patients with Turner syndrome. It will look closely at how taking steroid hormones effects the patient's rate of growth as well as the patient's ability to learn. In addition the study will investigate how different hormones (androgen and estrogen) work when given together as a combination.

All patients asked to participate in this study will receive growth hormone injections. However, half of the patients will receive an additional sex steroid hormone (oxandrolone) in the form of a pill. The other half of the patients will receive a placebo or "sugar pill". This will allow the researchers to determine if the combination of the hormones produces different results than growth hormone alone.

The study will last approximately 2 years. After 2 years of research the patients may qualify for an additional 2 years of treatment. Patients may benefit directly from this research with increased growth and improved ability to learn.

Turner syndrome is associated with short stature, multiple physical stigmata, and absent pubertal development. We propose to: (1) examine the effects of sex steroids (androgen) on multiple variables (growth rate, GH binding protein, IGF-I, and cognitive function), in the setting of supplemental growth hormone administration and (2) to investigate any synergistic or additive effects of the androgen and estrogen combination on the above variables.

• INCLUSION CRITERIA:

Girls with Turner syndrome will qualify to participate in this study if they meet the following criteria:

Karyotype diagnosis compatible with Turner syndrome.

No treatment with estrogen, androgen or growth hormone exceeding twelve months, and no treatment with either of these agents in the preceding 3 months.

Chronological age of 10.0 to 14.9 years.

Bone age less than or equal to 12 years.

EXCLUSION CRITERIA:

Prior treatment with estrogen, androgen, or growth hormone for more than twelve months.

Y component in peripheral karyotype.