2. To determine the effect of GenotropinTM on whole body protein turnover (WBPT), IGF-1 levels and cytokines. Utilizing the stable isotope 1-[13C] leucine, we will measure WBPT. Measurements of WBPT will be correlated with LBM and changes in height and weight velocity. This data will be compared to that from age matched normal children (archival data maintained by the PI). We will measure IGF-1 and the cytokines TNF-α, IL-6 and IL-10 at baseline and very six months. These measures will be correlated with height and weight velocity and IGF-1 levels. Cytokine levels will also be correlated with protein catabolism. This specific aim tests the hypothesis that chronically ill children have increased catabolism, caused by high levels of circulating cytokines and low levels of IGF-1, and that these abnormalities improve with GenotropinTM.