Hyperostosis Corticalis Generalisata (HCG), also known as Engelmann's Disease or Progressive Diaphyseal Dysplasia, is a rare genetic disorder characterized by excessive bone overgrowth and thickening throughout the skeleton. It is predominantly an autosomal dominant condition, meaning it can be inherited from one affected parent.
In HCG, there is a disturbance in the normal bone remodeling process, leading to an abnormal and excessive formation of bone tissue, particularly in the cortical (outer) layer of long bones. This results in the thickening of the bone cortices, making them denser and heavier. The overgrowth predominantly affects the long bones, such as the tibia and femur, but can also involve other bones of the skeleton.
Symptoms of HCG typically develop during childhood or adolescence and may include bone pain, muscle weakness, fatigue, and an overall reduction in physical activity. Additionally, individuals with HCG may exhibit a characteristic facies, with a prominence of the forehead, flattened nose, and a narrow opening between the eyelids.
Diagnosis of HCG involves clinical evaluation, imaging techniques like X-rays and bone scans, as well as genetic testing to identify specific mutations associated with the condition. Treatment options for HCG are limited, and management primarily focuses on alleviating symptoms and improving quality of life. This may involve the use of analgesics for pain relief and physical therapy to maintain muscle strength and flexibility.
While HCG is a chronic condition, its course and severity vary widely among affected individuals. Some may experience only mild symptoms and require minimal intervention, while others may have progressive bone abnormalities that may affect their mobility and require more extensive medical management.
