CDH1 and Bartsocas-Papas syndrome 1: Several previous EM studies have also described pathologic changes in bladder ultrastructure among IC/BPS patients, such denudation and loss of urothelial cell layers in HIC9,17, as well increased apoptotic activity and urothelial barrier defects due to downregulation of tight junction proteins such as E-cadherin and ZO-17,18.