FOP is caused by a point mutation in the ACVR1 gene, which results in an amino acid change in codon 206 (R206H) within the glycine‐serine (GS) activation domain of a BMP type I receptor, activin receptor‐like kinase‐2 (ALK2).3 This evidence concerns the gene ACVR1 and fibrodysplasia ossificans progressiva.