How Genetic Defects Cause Microcephaly (VIDEO) Columbia University Irving Medical Center This video is under embargo. Please login to access this video. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Caption Youtube link: https://www.youtube.com/watch?v=X9ysnvUrU6g In a very severe, genetic form of microcephaly, stem cells in the brain fail to divide, according to a new study that may provide important clues to understanding how the Zika virus affects the developing brain. Credit Columbia University Medical Center Usage Restrictions No restrictions 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.