CDHR1 (cadherin related family member 1) is a specialized protocadherin essential for photoreceptor structural integrity and function. It is highly expressed in cone and rod photoreceptors where it maintains the structural organization of outer segments 1. CDHR1 functions as a calcium-dependent cell-adhesion protein critical for photoreceptor cell morphogenesis and outer segment organization. Biallelic CDHR1 variants cause autosomal recessive retinal dystrophy presenting with marked clinical heterogeneity 2. The disease manifests as cone-rod dystrophy, rod-cone dystrophy, or maculopathy, typically with symptom onset between the fourth and sixth decades of life 3. Pathologically, mutations result in shortened photoreceptor outer segments and progressive photoreceptor cell death 1. Electrophysiologically, both rod and cone function are severely compromised, with electroretinography showing reduced scotopic and photopic responses 34. CDHR1 is among the most frequent causes of inherited macular dystrophy, accounting for 6.1% of genetically explained cases 5. Notably, some CDHR1 variants demonstrate incomplete penetrance, complicating genetic diagnosis 5. Gene therapy targeting CDHR1 has demonstrated durable morphological and functional rescue in murine models, sustaining improvement for 23 months and warranting clinical trial development 1.