Motor milestones in children with diastrophic dysplasia

Diastrophic dysplasia (DD), an autosomal recessive skeletal dysplasia, results in short-limbed short stature, generalized joint dysplasia, and spinal, hand, foot, and ear deformities. Children with DD experience both growth and motor developmental delays. To quantify the motor developmental delays, data on motor milestone attainment and other important characteristics were collected by retrospective questionnaire on 25 individuals with DD. Means and standard deviations were calculated for time to motor milestone attainment and are presented with minimum, maximum, 25th, 50th, 75th, and 90th percentile values. Percentages of individuals who could perform daily living and recreational tasks were tabulated. The mean times to milestone attainment for children with DD are all significantly longer than published means for nonaffected children. Notably, children with DD roll over at 5.2 ± 2.2 months, sit unsupported at 8.3 ± 2.3 months, pull up to a stand at 13.5 ± 5.8 months, and walk at 24.4 ± 9.2 months. The data presented here should be useful as preliminary reference standards for motor milestone attainment in children with DD.