Abstract
The phenomenon of catch-up growth has been known for a long time but its actual stimulus has remained unidentified. Involvement of growth hormone (GH) seems likely, but it is unknown whether normal GH secretion is an absolute prerequisite for catch-up growth. We present insight to this topic by describing a child with GH deficiency who showed a biphasic pattern of catch-up growth. During the first catch-up phase, she showed restricted catch-up growth in the absence of GH therapy, while she achieved nearly complete catch-up with GH therapy. Both periods of catch-up growth are compared separately with the response to GH therapy of age-matched, GH deficient patients with similar height deficit. This observation suggests that the first phase of catch-up growth in a child with severe growth retardation may be partially GH independent, while further catch-up requires normal GH levels.