Bone Abstracts

Objectives: Achondroplasia (ACH), caused by a mutation in the fibroblast growth factor receptor 3 gene (FGFR3), leads to inhibition of endochondral bone growth. Three potential treatments all targeting the FGFR3 on different levels of the pathway are under development. To compare the different approaches there is a need for precise measurements of efficacy. COLX and other biomarkers of bone growth are biological by-products of endochondral bone growth. A nationwide study of ACH children age 2–15 years is conducted evaluate the use of biomarkers as an indicator of short term bone growth.

Methods: 15 ACH children completed more than ≥6 months of growth measurements in an observational study. Growth velocity was evaluated by anthropometric measurements (arm-span, sitting and standing height) and blood samples were collected every 3 months for analysis of biomarkers reflecting bone turnover. The ACH children were compared to a healthy cohort with normal growth (n=194, 99 females, 95 males, range: 6.7–16.8 years). We aim to establish reference ranges for CXM in healthy children, to evaluate CXM in relation to age, sex, puberty and peak height velocity and in relation to other biomarkers of bone growth.

Results and Conclusion: Data from the initial 3 months of follow-up in ACH group is compared to the control group. Data analysis will demonstrate the potential of biomarkers as sensitive indicators of growth velocity and as indicators of efficacy in developing new treatments for ACH. Reference ranges using GAMLSS statistical approach will be constructed for age and sex-dependent SD-score for COLX and data for the ACH is plotted against the children with normal growth.

Disclosure: The authors declared no competing interests.