[Low height and rare diseases].

Low stature is the main reason of consultation in paediatric endocrinology. In a high percentage of cases, its etiology is clear and fundamentally answers to variants of normality. However, in approximately 20% of cases low stature is pathological and requires exhaustive studies. The association of rare diseases (RD) with low height is very frequent. In this article we review the etiology of low height, describing: - The genetic forms of the growth hormone (GH), whether isolated or associated with malformations of the average line or others. - Those which are of great importance due to their clinical repercussion, such as Turner's Syndrome, Noonan's Syndrome and Willi-Prader's Syndrome. - The frequent osseous dysplasias, in some cases with genetic alterations of the SHOX gene, situated in the short arm of the Xp chromosome. The importance of these diagnoses lies in the possibility of carrying out early and efficient treatment, in some of them, with GH. In conclusion, the diagnosis of rare diseases with low height is a current and normal challenge in paediatric endocrinology due to the great advances in molecular genetics and the possibility of treatment in some of them. It always involves a multidisciplinary approach due to the frequent association of pathology it presents, and, in its turn, it offers the possibility of carrying out timely genetic counselling.