IQCE (IQ motif containing E) is a ciliary protein that functions as a component of the EvC complex, a positive regulator of Hedgehog (Hh) signaling essential for limb development 1. IQCE anchors the EVC-EVC2 complex at the base of primary cilia through interaction with EFCAB7, creating a signaling microdomain that activates the transcription factor GLI2 1. This ciliary localization is critical for proper anteroposterior patterning during limb morphogenesis 2. Dysregulation of IQCE impairs Hh pathway activation and results in dysregulation of Hh-associated genes 2. Loss-of-function mutations in IQCE cause nonsyndromic postaxial polydactyly (PAP), characterized by supernumerary digits 2. Zebrafish models with IQCE dysfunction demonstrate a spectrum of ciliary defect phenotypes including body curvature, kidney cysts, left-right asymmetry, and retinal defects, confirming its role in cilia function 2. IQCE mutations account for one of eleven identified genes causing nonsyndromic PAP, positioned alongside variants in related pathway components EVC, EVC2, GLI1, and EFCAB7 3. The discovery of recurrent IQCE mutations across unrelated families establishes it as a significant PAP locus 2.