Hao-Fountain syndrome (HAFOUS) is a rare neurodevelopmental disorder caused by mutations in the ubiquitin-specific protease 7 (USP7) gene for endosomal recycling. The diagnosis often challenging due to nonspecific presentation of intellectual disability and developmental delay, accompanied dysmorphic facies. In this case, we present an 18-year-old female with (ID), attention-deficit/hyperactivi...