Growth hormone (GH) deficiency (GHD), when diagnosed during childhood or adolescence, can manifest as an isolated or a combined pituitary hormone deficiency, and it can vary in severity, ranging from severe (often defined as a peak GH following a stimulation test of < 3 ng/mL) to partial GHD (often defined as a peak GH of 3-7 ng/mL) (1). The gene discussed is GH1; the disease is hypopituitarism.