We present the case of an adult patient with growth hormone (GH) insufficiency and hereditary motor and sensory neuropathy type 1. Stopping GH replacement at the attainment of final height was associated with a marked reduction in power and mobility, resulting in the patient becoming wheelchair bound. GH replacement was assessed in a double-blind placebo-controlled trial. During the GH replacement arm of the trial, the patient’s mobility and independence returned to previous levels. We suggest that the indications for GH replacement in adults should take account of other medical problems, in particular neuromuscular disorders, as well as the degree of GH deficiency.