Endocrine Abstracts

Background: Estimates for the prevalence of SHOX mutation in children with short stature vary from 2 to 15%. Unless specific clinical and radiological signs are sought these patients can be misdiagnosed as idiopathic short stature. An evidence based clinical scoring system has been published to identify these patients; more recently characteristic radiological signs have also been identified in bone age X-rays. To our knowledge there has not been a survey in the UK evaluating the prevalence of these features.

Aim: To evaluate the phenotypical and radiological signs of a cohort of patients with confirmed SHOX mutation, which may be used to identify patients with short stature for genetic testing.

Method: Multicentre retrospective case review in the South West region.

Results: Fifteen patients were identified from eight hospitals. Mean age at diagnosis was 8.75 years with mean height −2.63 SDS (range −4.8 to −0.77). 14/15 had a familial history of short stature (75% had first degree relative with Leri Weill syndrome/SHOX mutation). 9/15 patients had documented disproportion. 7/13 eligible patients had a sitting height/height ratio performed: 86% had a ratio >55.5%. Five had an arm span measured: 100% had an arm span/height ratio <96.5%. 73% had a BMI >50th percentile. Nine patients had clinical rhizomelia, four Madelung deformity, and four bowing of forearm. 11 patients had a bone age X-ray: eight showed signs of triangularisation, pyramidalisation, and/or lucency, one result was equivocal and two were too young for analysis.

Conclusions: Analysis of our cohort identified key features that would prompt SHOX mutation analysis in a child with short stature. This included a positive family history, disproportion, and characteristic signs on a standard bone age X-ray. Approach to measuring disproportion varied throughout the South West. We propose a simple screening tool to identify patients more likely to have SHOX mutation.