The study population will consist of children with newly diagnosed growth hormone deficiency (GHD), between the ages of 1-17 years. The clinical evidence will be provided by one or more of the following criteria: delayed bone age, growth deceleration, short stature (more than 2 SD bellow the mean for the subject's age) and/ or height more than1.5 SD below the predicted mid-parental height. The biochemical diagnosis of GHD will be established by an abnormal growth hormone stimulation test and low IGF-1 and IGFBP-3 (growth factors). The growth hormone stimulation test will be performed following the standard Endocrinology Clinic protocol. The growth hormone stimulation test is considered the "gold standard" to diagnose Growth Hormone Deficiency. This test is part of the standard clinical practice to diagnosed GHD. An abnormal test is defined as a post stimulation Growth Hormone level less than10 ng/mL.