Clinical meaning of high bone mineral density (Part I). Genetic diseases causing high bone mass

Over the nearly 40-year history of dual-energy X-ray absorptiometry (DXA), the main focus has been on the diagnosis of low bone mineral density (BMD), i.e. osteoporosis, which has been the subject of many domestic and foreign publications. The problems associated with increased BMD and related not only to the difficulty of interpreting the results, but also to further patient management tactics have been covered significantly less. Most often, such cases pass unnoticed in routine clinical practice due to the orphan nature of many diseases leading to the development of pathologically high bone density, and, as a rule, are interpreted as a manifestation of osteoarthritis. Of course, arthrosis, scoliosis and other joint deformities (especially in the spine) are the cause of overestimation of BMD in most clinical situations. However, bone dysplasia, manifested by a diffuse or focal increase in BMD, can, like osteoporosis, be complicated by low-traumatic fractures; neurological and other complications, potentially leading to disability, also occur. Despite the extremely rare occurrence of these diseases, doctors’ insufficient awareness about the peculiarities of the clinical and radiological pattern and the course of sclerosing bone dysplasias can lead to errors in making a diagnosis, and first of all, to incorrect interpretation of the results of DXA. Our review aims to briefly describe genetically determined pathologies that cause an excessive increase in BMD, in order to attract the attention of the medical audience to this problem.