Severe autoimmune lymphoproliferative syndrome phenotype in a pediatric patient with a germline FAS gene variant Authors: Alexandra Dreyzin MD MS1; Jinjun Cheng MD PhD2, David Leitenberg MD PhD3, and Yaser Diab MBBS1Center for Cancer and Blood Disorders, Children’s National Hospital, Washington, DCDivision of Pathology and Laboratory Medicine, Children’s National Hospital, Washington, DCDepartment of Microbiology, Immunology and Tropical Medicine, The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA.