The Puzzle of Autism (IMAGE) Johns Hopkins Medicine Caption The structure of the protein NHE9 is one piece of the puzzle of what causes autism. Credit Kalyan Kondapalli and Rajini Rao Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.