Growth Hormone Treatment for Idiopathic Short Stature.

ISS is the commonest cause of short stature and poor growth and is arbitrarily defined as a height < -2 SDS without an identified cause. ISS consists largely of normal children with the remainder unrecognised conditions, mainly syndromes and genetic (monogenic and polygenic) causes. Growth response to rhGH is widely variable reflecting the heterogeneity of ISS. Further identification of genetic causes of ISS will better characterise treatment response. rhGH during childhood has been shown in RCTs to improve adult height by approximately 4 cm which is less than seen in other treated growth disorders. Factors that influence response include; younger age, longer birth length, lower height compared to mid-parental height, delayed bone age and larger rhGH dose. The evidence that short stature is associated with psychological well-being and quality of life is minimal and that rhGH could improve this is scant. Further research in this area is urgently required.