Fibrous dysplasia (FD) is a congenital, non-hereditary bone disease with a clinical presentation ranging from mild monostotic disease to the more rare polyostotic disease (PFD) sometimes accompanied by extra-skeletal involvement such as endocrinopathies (McCune-Albright Syndrome, MAS) or soft tissue tumors, myxomas (Mazabraud syndrome).

To characterize the biochemical, radiological, and histological spectrum and clinical management and treatment outcomes of FD/MAS, we initiated the PROspective study in Fibrous Dysplasia (PROFID) to follow patients prospectively. The study was started locally, however we are in the process of including more centers the coming year. To date, there are two university medical centers in The Netherlands actively enrolling patients (both adults and children) in the study, and hopefully more are expected to join in the coming years.

We are evaluating the natural course of the disease, as well as treatment outcome of both surgical and medical therapies by assessing symptoms of pain, physical function, markers for bone turnover as determinants for disease activity, radiological aspects at time of diagnosis and skeletal burden score and disease quantification by nuclear imaging before and after treatment. In addition we assess GNAS-mutation related comorbidity like precocious puberty, myxomas, hepatobiliary neoplasms and intrapancreatic mucinous neoplasms, and mortality, as well as psychological function by using validated questionnaires.

The PROFID study aims to aid in expanding our knowledge on FD/MAS, and further characterizing this rare bone disease. Furthermore, by creating the PROFID network we hope to improve the diagnosis and treatment of the disease as well as the information on the disease and increase further doctor and patient awareness.