IQCB1 (IQ motif containing B1) is a ciliary protein essential for ciliogenesis and photoreceptor function. It associates with CEP290/NPHP6 to regulate early cilia formation 12 and controls BBSome complex integrity, particularly the presence of BBS2 and BBS5 subunits, facilitating ciliary targeting of BBSome cargos 3. IQCB1 dysfunction impairs ciliary axoneme structure and outer segment development, with reduced CEP290 protein levels providing a mechanism for aberrant ciliary gating 4. IQCB1 mutations cause Leber congenital amaurosis (LCA) and Senior-Loken syndrome (SLS), characterized by early-onset severe cone-rod dystrophy with rapid photoreceptor degeneration 56. Patients with IQCB1 variants present retinopathy as early as infancy, with nystagmus as the most common initial sign in 86.4% of cases and extinguished electroretinograms in most patients 7. While cone photoreceptors are preferentially preserved, most patients develop severe vision loss with dysfunctional retinal structure 56. Nephronophthisis develops later, with renal failure appearing around age 26 years in approximately half of patients 6. IQCB1-retinopathy shows phenotypic variability; notably, dissociation between severely reduced retinal function and relatively preserved retinal structure makes it a promising candidate for gene therapy intervention via AAV-mediated gene augmentation 46.