| Affiliation: | 1. McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA Department of Pediatrics, Taibah University, College of Medicine, Madinah, Saudi Arabia;2. Division of Interventional Radiology, The Russell H. Morgan Department of Radiology and Radiologic Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA;3. Department of Orthopedic Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA;4. McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA |
| Abstract: | Hereditary multiple exostoses (HME), also known as hereditary multiple osteochondroma (HMO), is an autosomal dominant disorder caused by pathogenic variants in exostosin-1 or -2 (EXT1 or EXT2). It is characterized by the formation of multiple benign growing osteochondromas (exostoses) that most commonly affect the long bones; however, it may also occur throughout the body. Although many of these lesions are clinically asymptomatic, some can lead to chronic pain and skeletal deformities and interfere with adjacent neurovascular structures. Here, we report two unrelated probands that presented with a clinical and molecular diagnosis of HME with venous malformation, a clinical feature not previously reported in individuals with HME. |
