The majority of FOP patients carry a heterozygous missense mutation (c.617G > A; p.R206H) in the ACVR1 gene, which encodes activin A type I receptor /activin receptor-like kinase 2 (ACVR1/ALK2), a morphogenetic protein (BMP) type I receptor (Shore et al., 2006). This evidence concerns the gene ACVR1 and fibrodysplasia ossificans progressiva.