1. Study group - Provision of standard weekly dose of SQ rGH (0.35 mg/kg/week divided into 3 doses, each dose being given at the conclusion of dialysis therapy) for up to 2 years to growth retarded (Height SDS < -1.88 or Height velocity < -1.88 SD) children receiving HD who are naïve to rGH or who have not been on rGH for at least 12 months. Inclusion criteria are: medically cleared for SQ rGH Rx (14); growth potential based on Tanner stage 1 with open epiphyses on Bone Age radiographs (Bone age < 12 years); expected to require HD for at least 6 more months; at least 6 months of standardized historical pre-study anthropometric data (including stadiometer height). Exclusion criteria include all medical factors that indicate that rGH therapy should not be used (14), e.g., poor nutritional status, poorly controlled acidosis, poor dialysis adequacy (defined by Kt/V < 1.2), poorly controlled renal osteodystrophy (PTH > 800). Once the complicating factor is addressed and corrected, the child may be considered for the study.