ESPE Abstracts

Classical growth hormone insensitivity (GHI) is caused by a defect of the growth hormone receptor and is characterized by severe postnatal growth failure, craniofacial disproportion, IGF-I deficiency and normal or elevated levels of growth hormone. This is a rare condition. With the development of new genetic techniques during the last two decades other monogenetic defects resulting in milder forms of GHI have been identified. These include genes involved in the GH-IGF-I axis: STAT5B, IGF-I, IGF1R, IGFALS and PAPPA2. These defects present with a variable phenotype and biochemical profile and are likely to be more prevalent than the classical severe form of GHI. With the increasing availability of genetic investigations it is a challenge for the clinician to identify patients with short stature that should be analysed for further genetic analysis of the GH-IGF-I axis. Clinical scores have been developed to help the clinician in this diagnostic process. Recently a score for IGF1R analysis was proposed, including birth weight and/or length < -1 SDS, height at presentation < -2.5 SDS, head circumference < -2 SDS and IGF-I level > 0 SDS. If a patient meets at least three criteria IGF1R analysis is recommended. In this session the clinical and biochemical features of nonclassical causes of GHI will be discussed and diagnostic strategies will be proposed.