Medical co-morbidities and developmental outcomes of children with autism and Down syndrome

Down syndrome (DS) is an inherited genetic disorder affecting approximately 1 in every 691 live births in the United States. Autism is a neuro-developmental disorder affecting about 1 in 68 births in the United States. Both diseases poses a serious public health concern. In recent years, there has been an increase in the number of children with DS who are also being diagnosed with autism. Although the association of autism with DS is said to be uncommon, the co-occurrence of the two disorders has important implications for understanding common features such as medical co-morbidities and developmental outcomes among these children. Most studies are focused solely on various co-morbidities in either children with autism or children with DS but not on the impacts of developmental outcomes among these children with medical co-morbidities. The present study aimed to assess whether any co-existing medical co-morbidities associated with DS may predispose children to have lower developmental outcomes. This study also focused on to compare the developmental outcomes of children with DS alone and children with DS and autism. A cross-sectional study among 520 children with DS was conducted at the Down Syndrome Clinic of Houston at Texas Children’s Hospital. The data collected between June 2006 to September 2011 were used for this study. The developmental outcomes were measured using the Capute Scales which calculated the developmental quotient (DQ) among these children. DQ (outcome variable) by various medical co-morbidities were compared between children with DS and children with both DS and autism using Fisher\u27s exact test. Predictions of DQ for all children with DS were assessed using multiple linear regression model. For children with both DS and autism, predictions of DQ were assessed using Wilcoxon rank-sum test. Results from this study suggest a significant association exists between DQ and OSA and seizure among children with DS alone and between only OSA and DQ among children who were diagnosed with DS and autism. This is the first observational study conducted at the regional DS clinic to look at the associations between different medical co-morbidities and developmental outcomes among children with both DS and autism. Further research on population-based studies is needed to investigate the associations between developmental outcomes and other medical co-morbidities among children with both DS and autism