Functional Independence Assessment in Children, Adolescents, and Young Adults with Achondroplasia: A Multicenter Cross-sectional Study Using the WeeFIM Scale

Background/Objectives: Achondroplasia is the most common skeletal dysplasia, affecting 1 in 25,000 births. Limited research exists on the assessment of functional independence using standardized tools across the lifespan of individuals with achondroplasia. The WeeFIM scale provides a comprehensive evaluation of daily living skills across multiple functional domains. This study aimed to assess the functional independence levels in children, adolescents, and young adults with achondroplasia using WeeFIM and analyze functional capabilities. Methods: This multicenter cross-sectional study included 51 participants aged 6–47 years with confirmed achondroplasia. Data were collected through standardized WeeFIM assessments from medical centers and online surveys (2021–2024). WeeFIM evaluates 18 functional items across 3 domains: self-care (8 items), mobility (5 items), and cognition (5 items), scored 1–7 (complete dependence to independence). Results: Participants included 29 males (56.9%) and 22 females (43.1%). Most (78.4%) were diagnosed during infancy. The mean functional scores were the highest for cognition (34.2/35, 97.7%), followed by self-care (52.8/56, 94.3%) and mobility (32.1/35, 91.7%). All participants achieved near-complete independence in cognitive functions. Mobility tasks, particularly stair climbing and bathtub transfers, showed the greatest score variability. Functional independence increased with age, with significant improvements during early childhood to school-age transition. Conclusions: Children, adolescents, and young adults with achondroplasia demonstrate high functional independence across daily activities, with cognitive abilities unaffected. Although specific mobility challenges exist, most participants achieve independence with appropriate accommodations. These findings provide valuable baseline data for clinical care planning and support optimistic functional outcomes across the lifespan of patients with achondroplasia.