Functional Change in a Child With Achondroplasia Following 12 Months Treatment With Vosoritide-A Case Report

Achondroplasia is the most common form of skeletal dysplasia. Over the last 24 months, a new treatment (vosoritide) is now available to promote endochondral growth through a daily injection. While research has identified increased annualized growth velocity in children with achondroplasia receiving vosoritide injections, there is currently little information on functional change and independence in self-care following this treatment. Here, we present a 5-year-old boy with achondroplasia who received vosoritide injections for 12 months. His functional performance was measured using the Functional Independence Measure for Children (WeeFIM). He was found to have a slightly higher level of independence when compared to age-matched peers with achondroplasia, and his rate of improvement in independence skills was twice that recorded in a previous study monitoring independence in children with achondroplasia following 12 months on vosoritide. When compared with WeeFIM normative data from average-statured children across the 12 months from 4 to 5 years, our child demonstrated almost three times the change for total WeeFIM and Self-Care domain scores and nine times the change across the Mobility domain scores, indicating a rapid increase in independence development. Our findings suggest that vosoritide may support the improvement of functional independence in children with achondroplasia receiving vosoritide to increase bone growth.