Cutaneous-Skeletal Hypophosphatemia Syndrome

Cutaneous-skeletal hypophosphatemia syndrome (CSHS) is a rare condition that primarily affects the bones and skin. People with this condition have skeletal dysplasia and a variety of skin abnormalities such as epidermal nevi (an overgrowth of the top layer of skin) and moles. Other common features include hypophosphatemia which can be associated with bone pain, limb length discrepancies, bone deformities, and impaired mobility. CSHS occurs sporadically in people with no family history of the condition. It is caused by somatic mutations in the RAS genes. Medications such as Calcitrol and phosphate supplementation are typically prescribed to treat the signs and symptoms of the condition. However, more directed therapies are in development.