A Rare Case of Hao-Fountain Syndrome Mimicking Fragile X Syndrome

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/hyperactivity (ADHD), facies who had undergone single nucleotide polymorphism (SNP) microarray fragile X polymerase chain reaction (PCR) testing five years prior diagnosis, both returning negative results genetic anomalies. patient was managed symptomatically ADHD until recently when topic possible condition reintroduced family, were agreeable referral medical geneticist repeat testing. Repeat testing, but now whole-exome sequence (WES) analysis, revealed pathogenic variant USP7 gene, prompting syndrome. Our continues be disability. Educational resources support group information also shared discussed her family wake diagnosis.