FLNB and atelosteogenesis type I: Atelosteogenesis type I (AOI) is a disease of autosomal dominant inheritance associated with mutations in the filamin B (FLNB) gene, located on chromosome 3p14, which encodes the filamin B protein.1 This syndrome includes a spectrum of phenotypes that may vary from mild, such as Larsen syndrome (LS) and spondylocarpotarsalsynostosis (STC), to severe conditions, such as atelosteogenesis type III (AOIII), and boomerang dysplasia.