Developmental milestones in infants and young Australasian children with achondroplasia

Background: Achondroplasia, the most common form of chondrodysplasia (inherited skeletal dysplasia), is characterized by a significant delay in the development of communication and motor skills, particularly during the first 2 years. Although some information regarding timing of development for children with achondroplasia is available, no study has evaluated simultaneously the pattern of skill development across multiple key developmental areas. Method: This study used a retrospective questionnaire to quantify developmental data on milestone achievement. Twenty families of children with achondroplasia throughout Australia and New Zealand were asked to document age of acquisition for 41 gross motor, fine motor, and communication and feeding milestones. More than one half of the items assessed were milestones identified in the Australian State Government Personal Health Record Books. The results are compared with previously available information regarding development of motor skills by a cohort of American children with achondroplasia. Results: Although the results support previously reported delays in gross motor and communication skill development, fine motor development does not seem to be as delayed as previously suggested. Information on development of self-feeding skills is presented for the first time and occurs later in this group than the typically developing population. We describe 2 distinctive and previously unreported methods of transitioning between static positions commonly used by children with achondroplasia. Conclusion: Delays were reported across gross motor and communication and feeding skills but were not observed during development of fine motor skills. Additional information is also offered regarding a variety of unusual movement strategies demonstrated by young children with achondroplasia.