Heterozygous mutations in Gli3 account for several dominant diseases of variable severity, including Greig cephalopolysyndactyly syndrome (GCPS; MIM: 175700) [90,91], Pallister-Hall syndrome (MIM: 146510) [92], preaxial polydactyly type IV (MIM: 174700) and postaxial polydactyly types A1 and B (MIM: 174200) [93,94]. This evidence concerns the gene GLI3 and Greig cephalopolysyndactyly syndrome.