Endocrine Abstracts

Introduction: The chondrodysplasias are a heterogeneous group of genetic conditions affecting growth and form of the skeleton. As genetic knowledge has improved and genetic testing has become increasingly available, we hypothesize that over the past 10 years there has been an increase in the number of children where a genetic diagnosis is reached.

Aims: To ascertain if there had been an increase in the number of chondrodysplasias confirmed by genetic testing over the past 10 years.

Methods: All children seen within the combined complex bone disorder clinic (endocrinology, orthopaedic, occupational therapy and genetic input) at the Royal Hospital for Sick Children, Glasgow between October 2002 and July 2012 with a suspected chondrodysplasia were studied. Case notes for eligible patients were analysed to provide information on the diagnosis and how this was made (clinically/radiologically/on genetic testing).

Results: Of the 318 children identified, 69 with chondrodysplasias were eligible. 44 patients (64%) had short stature and 28 (41%) had disproportion. Disproportion was more correlated with a positive genetic test (61%) than short stature (43%). Of 69 patients, 44 had genetic testing, of which 68% were positive. These included 16 (36%) who were tested for mutations in FGFR3 (achondroplasia/ hypochondroplasia). This test was positive in 5 of 6 cases from 2007 to 2012 and only 6 of 10 from 2002 to 2006. There was no change in the trend of genetic testing over the study period. Of 69 cases, X-ray was diagnostic in 31 (45%) and clinical examination in 19 (28%). There was no change in these modalities over the study period.

Conclusion: Despite advances in genetic testing there has been no clear increase in the use of genetic testing in patients with chondrodysplasias over the last 10 years. Clinical and radiological examination remain the mainstay of diagnosis.