Polydactyly is a clinically and genetically heterogeneous disorder. In the current report, we present a five-generation Chinese family with non-syndromic pre-axial polydactyly with thumb polydactyly (pre-axial polydactyly type I (PPD-I)) as a major clinical feature. Using whole-exome sequencing (WES), a novel nonsense mutation c.714T>A (p.Y238*) of the glioma-associated oncogene family zinc-finger 3 gene (GLI3) was identified as the pathogenic mutation for this family. Our study has, for the first time, suggested the possible contribution of GLI3 in the patheogenesis of PPD-I, and demonstrated that WES provided an applicable diagnostic tool for identifying mutations in disorders with highly genetical heterogeneity such as polydactyly.