GLI3 and Pallister-Hall syndrome: Pallister-Hall syndrome is caused by truncating variants in the middle third of the GLI3 gene.10–12 The truncation of GLI3 causes an overexpression of GLI3R, which is believed to be the key difference between Pallister-Hall and the GLI3-mediated polydactyly syndromes.9 11 Although multiple attempts have been made, the clinical and genetic distinction between the GLI3-mediated polydactyly syndromes is less evident.