Growth hormone (GH), insulin-like growth factor-1 (IGF1) and several related molecules are involved in the growth regulation axis at both pre and postnatal life. The advances in molecular biology techniques have improved the way of identifying genetic defects in different elements of the GH-IGF1 axis in children with short stature. On the other hand, the use of new GH assays have revealed the presence of GH with no biological activity or increased amounts of less active GH isoforms in the circulation, which could potentially be the cause of growth retardation in certain children with short stature. Clinically, the genetic defects might result in either hormone deficiency or resistance, showing the importance of evaluating both GH secretion and GH responsiveness in a short child. In the present article, the main genetic defects within the GH-IGF1 axis are reviewed with focus in their clinical repercussion and their importance in the differential diagnosis of idiopathic and familial short stature. In addition, a short review on the genetic abnormalities found in two of the most important pituitary transcription factors will be presented.
GH; IGF1; Growth; Short stature; Molecular genetics