ABSTRACT GLI3 is the gene responsible for Greig cephalopolysyndactyly syndrome (GCPS), Pallister-Hall syndrome (PHS) and Postaxial polydactyly type-A (PAP-A). Genetic polydactyly mice such as Pdn/Pdn (Polydactyly Nagoya), Xt(H)/Xt(H) (Extra toes) and Xt(J)/Xt(J) (Extra toes Jackson) are the mouse