Perthes Disease

Floating-Harbor Syndrome (FHS; OMIM #136140) is an ultra-rare autosomal dominant genetic condition characterized by expressive language delay, short stature with delayed bone mineralization, a triangular face with a prominent nose, and deep-set eyes, and hand anomalies. First reported in 1973, FHS is associated with mutations in the SRCAP gene, which encodes SNF2-related CREBBP activator protein. Mutations in the CREBBP gene cause Rubinstein-Taybi Syndrome (RSTS; OMIM #180849, #613684), another rare disease characterized by broad thumbs and halluces, facial dysmorphisms, short stature, and intellectual disability, which has a phenotypic overlap with FHS. We describe a case of FHS associated with a novel SRCAP mutation and characterized by Perthes disease, a skeletal anomaly described in approximately 3% of patients with RSTS. Thus Perthes disease can be added to the list of clinical features that overlap between FHS and RSTS.