Unexpected high frequency of skeletal dysplasia in idiopathic short stature and small for gestational age patients

ObjectiveTo assess the prevalence of skeletal dysplasias (SDs) in patients with idiopathic short stature (ISS) or small for gestational age (SGA) status.SettingRare Endocrine/Growth Diseases Center in Paris, France.DesignA prospective study on consecutive patients with ISS and SGA enrolled from 2004 to 2009.MethodWe used a standardized workup to classify patients into well-established diagnostic categories. Of 713 patients with ISS (n=417) or SGA status (n=296), 50.9% underwent a skeletal survey. We chose patients labeled normal or with a prepubertal slowdown of growth as a comparison group.ResultsDiagnoses were ISS (16.9%), SGA (13.5%), normal growth (24.5%), transient growth rate slowing (17.3%), endocrine dysfunction (12%), genetic syndrome (8.9%), chronic disease (5.1%), and known SD (1.8%). SD was found in 20.9% of SGA and 21.8% ISS patients and in only 13.2% in our comparison group. SD prevalence was significantly higher in the ISS group than in the comparison group, especially (50%) for patients having at least one parent whose height was ConclusionSD may explain more than 20% of cases of growth retardation ascribed to ISS or SGA, and this proportion is higher when parental height is