Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Observational
Official Title: Cardiometabolic Profiles of Pubertal Boys With Klinefelter Syndrome With or Without One Year of Exogenous Testosterone Treatment
Brief Summary: This study plans to learn more about how to measure the way the the body's energy system works in boys with Klinefelter syndrome, including the heart, lungs, muscles, and liver. This is important to know so that investigators understand how hormones and an extra X chromosome relate to diseases such as diabetes, extra weight gain, heart disease and liver diseases.