Zone of Polarizing Activity Regulatory Sequence Mutations/Duplications with Preaxial Polydactyly and Longitudinal Preaxial Ray Deficiency in the Phenotype: A Review of Human Cases, Animal Models, and Insights Regarding the Pathogenesis

<div>(a) SHH is posteriorly located in the Zone of Polarizing Activity (ZPA, marked with dark green). The SHH protein is a diffusible morphogen. Normally, SHH activity (light green color) extends anteriorly to reach digit 2. There is no SHH expression or activity in the zones of digit 1/radius. (b) Anterior ectopic expression of SHH results in PPD (preaxial polydactyly).</div>

BioMed Research International

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Figure 1

Figure 1: Zone of Polarizing Activity Regulatory Sequence Mutations/Duplications with Preaxial Polydactyly and Longitudinal Preaxial Ray Deficiency in the Phenotype: A Review of Human Cases, Animal Models, and Insights Regarding the Pathogenesis 

Figure 1 | Zone of Polarizing Activity Regulatory Sequence Mutations/Duplications with Preaxial Polydactyly and Longitudinal Preaxial Ray Deficiency in the Phenotype: A Review of Human Cases, Animal Models, and Insights Regarding the Pathogenesis 