Understanding the clinical morbidity and mortality of fibrodysplasia ossificans progressiva: a systematic literature review.

backgroundFibrodysplasia ossificans progressiva (FOP) is an autosomal dominant ultra-rare disease characterized by progressive episodic multi-focal heterotopic ossification of skeletal muscle, ligaments, tendons, and fascia. Comprehensive characterization and understanding of the natural disease history of FOP, including mortality, comorbidities, and medication use, is currently limited.

objectiveThis systematic review, which we believe is the first of its kind, aims to synthesize current knowledge on the morbidity, mortality, and medication use associated with FOP.

methodsA systematic literature review (SLR) was conducted utilizing various databases including PubMed, Embase, the Cochrane Central Register of Controlled Trials, the Trip database, and National Institute for Health and Care Excellence documents. The search was limited to studies involving humans, but was not restricted based on language. The studies used reported at least one of the following outcomes: mortality, comorbidity, and medication use; any clinical trials that were solely designed to evaluate a symptomatic treatment for FOP, such as flare-ups and pain, were excluded. Two independent reviewers reviewed and selected the included studies of the review, and extraction was done by one reviewer with cross-check performed by the other person. The Joanna Briggs Institute Critical Appraisal Checklist, specifically designed for studies reporting prevalence data, was used to assess the quality of studies. The SLR was registered on Prospero (CRD42022366914).

resultsIn total, 32 publications were selected for review. These studies included a wide range of participants age (0.1-78 years), study duration (1 day-33 years), and sample size (3-299 patients). Ten studies reported information on mortality, 26 studies reported on comorbidities, and 12 reported information on medication use. The three organ systems most affected by the conditions studied were, in order of severity, the cardiovascular (40-70%), skeletal (50-65%), and respiratory (20-42%).

conclusionsAlthough FOP is an ultra-rare disease, the available literature demonstrates that it is associated with excess morbidity and mortality. Our review synthesized all available published estimates of epidemiologic landscape of FOP and demonstrates the need for future work to better understand this rare disease.