KOBAYASHI, Y., SUZUKI, H., KONNO, T., TADA, K. and YAMAMOTO, T.Y. Ultrastructural Alterations of Paneth Cells in Infants Associated with Gastrointestinal Symptoms. Tohoku J. exp. Med., 1983, 139 (3), 225-230 -Paneth cells containing abundant and large inclusion bodies found in patients with acrodermatitis enteropathica have been considered as a consistent and characteristic abnormality of this disease. We examined 34 children with gastrointestinal symptoms due to a wide variety of basic diseases and found similar abnormal Paneth cells in most of them, particularly in infants under the age of one year. This abnormality, according to our findings, is attributed to the secondary effect of zinc deficiency due to malnutrition.