Genotype-phenotype correlations in a case of fibrodysplasia ossificans progressiva: a case report

Fibrodysplasia ossificans progressiva (FOP) is an ultrarare autosomal dominant genetic disorder. Most of the musculoskeletal characteristics of FOP are related to dysregulated chondrogenesis. Activating mutations of activin receptor A type I (ACVR1), a bone morphogenetic protein (BMP) type I receptor, are responsible for the skeletal and nonskeletal features. Characteristic features include congenital bilateral hallux valgus malformation and early-onset heterotopic ossification occurring spontaneously or, more frequently, precipitated by trauma. As disease progresses, thoracic insufficiency syndrome appears, with respiratory distress, pneumonia and right-sided heart failure. Diagnosis is confirmed by the identification of a heterozygous pathogenic variant in the ACVR1/ALK2 gene. Avoiding unnecessary surgical procedures, prescribing prophylactic corticosteroids, preventing falls represent essential interventions for care management.