Typical features are reduced muscle strength, altered body composition, obesity, low energy expenditure, short stature and delayed bone age.36 As GH secretion can be reduced, GH treatment has positive effects on linear growth.39,40 Indeed, different studies have also postulated a beneficial effect of GH therapy on body composition of these patients.41 In fact, a recent Spanish study showed increased lean mass, decreased fat mass and raised neural activation in different cerebellar areas in treated individuals.42 The gene discussed is GH1; the disease is obesity due to melanocortin 4 receptor deficiency.