The SHOX gene and the short stature. Roundtable on diagnosis and treatment of short stature due to SHOX haploinsufficiency: How genetics, radiology and anthropometry can help the pediatrician in the diagnostic process padova (April 20th, 2011)

The growth of the human body depends from a complex interaction between nutritional, environmental and hormonal factors and by a large number of different genes. One of these genes, short stature homeobox (SHOX), is believed to play a major role in growth. SHOX haploinsufficiency is associated with a wide spectrum of conditions, all characterized growth failure such as Leri-Weill dyschondrosteosis , Turner syndrome, short stature with subtle auxological and radiological findings and the so called “idiopathic short stature” (short stature with no specific findings other than growth failure). The document was prepared by a multidisciplinary team (paediatric endocrinologists, paediatrician, radiologist, geneticist and epidemiologist) to focus on the investigation of children with suspected SHOX- deficiency (SHOX-D) for an early identification and a correct diagnostic work - up of this genetic disorder. On the basis of a number of screening studies, SHOX-D appears to be a relatively frequent cause of short stature. The following recommendations were suggested by our multidisciplinary team: (i) a careful family history, measurements of body proportions and detection of any dysmorphic features are important for the suspect of a genetic disorder ,(ii)the presence of any combination of the following physical findings, such as reduced arm span/ height ratio, increased sitting height/height ratio, above average BMI, Madelung deformity, cubitus valgus, short or bowed forearm, dislocation of the ulna at the elbow, or the appearance of muscular hypertrophy, should prompt the clinician to obtain a molecular analysis of the SHOX region, (iii) it is of practical importance to recognise early or mild signs of Madelung deformity on hand and wrist radiographs, (iv) growth hormone ,after stimulation test, is usually normal . However, treatment with rhGH may improve final adult height; the efficacy of treatment is similar to that observed in those treated for Turner syndrome