Ehlers-Danlos/osteogenesis imperfecta syndrome

Ehlers-Danlos/osteogenesis imperfecta syndrome (also known as Ehlers-Danlos syndrome arthrochalasia type with overlap features, or EDS/OI overlap syndrome) is an extremely rare heritable connective tissue disorder that combines features of both Ehlers-Danlos syndrome (EDS) and osteogenesis imperfecta (OI). This condition is caused by mutations in genes encoding type I collagen, particularly COL1A1 or COL1A2, which result in defective collagen processing. Because type I collagen is a major structural protein throughout the body, the disorder affects multiple organ systems including the musculoskeletal system, skin, and connective tissues broadly. Key clinical features include marked joint hypermobility, recurrent joint dislocations (particularly of the hips, which may be congenital), skin hyperextensibility, easy bruising, bone fragility with recurrent fractures, osteopenia or osteoporosis, short stature, and blue sclerae. Some patients may also exhibit kyphoscoliosis, muscle hypotonia, and tissue fragility. The combination of joint laxity typical of EDS with the bone fragility characteristic of OI distinguishes this overlap syndrome from either condition alone. There is no cure for Ehlers-Danlos/osteogenesis imperfecta syndrome. Management is supportive and multidisciplinary, involving orthopedic care for fractures and joint instability, physical therapy to strengthen muscles and protect joints, and monitoring for skeletal complications. Bisphosphonates may be considered to address bone fragility, similar to their use in osteogenesis imperfecta. Genetic counseling is recommended for affected individuals and their families. Patients benefit from coordinated care involving geneticists, orthopedic surgeons, physiotherapists, and other specialists.

Common questions about Ehlers-Danlos/osteogenesis imperfecta syndrome