This study revealed three patients with familial gigantiform cementoma (FGC) carried the heterozygous mutation c.1067G>A (p.Cys356Tyr) in the ANO5 gene which was not found in 8 juvenile ossifying fibromas, 5 polyostotic fibrous dysplasia and 5 florid cemento‐osseous dysplasia. This evidence concerns the gene ANO5 and fibrous dysplasia.