FLNB and Spondylocarpotarsal synostosis: Previous studies have shown that heterozygous missense variations in FLNB lead to a spectrum of severe SDs including atelosteogenesis type I (AOI, MIM #108720), atelosteogenesis type III (AOIII, MIM #108721), Boomerang dysplasia (MIM #112310), Larsen syndrome (MIM #150250), and spondylocarpotarsal synostosis syndrome (MIM #272460).