ATP and GTP (IMAGE) University of California - San Diego Caption Healthy brains require a balance of two energy sources -- ATP and GTP -- regulated by the gene AMPD2. A mutation in the gene can result in pontocerebellar hypoplasia, a neurodegenerative disease afflicting children. Credit Illustration courtesy of Evgeny Onutchin, Buryat Studio Usage Restrictions Use illustration credit. 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.