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

ABSTRACT 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.