CNGB1 encodes the β1 subunit of the rod photoreceptor cyclic nucleotide-gated (CNG) ion channel, a ligand-gated cation channel controlled by cyclic guanosine monophosphate (cGMP) 1. This channel functions as a molecular switch in the outer segment plasma membrane, converting light-mediated changes in cGMP into voltage and Ca²⁺ signals essential for phototransduction 1. CNGB1 is also expressed in olfactory sensory neurons 2. Biallelic mutations in CNGB1 cause autosomal recessive retinitis pigmentosa (RP45), a progressive rod-cone dystrophy 31. Disease-causing variants include 84 documented mutations spanning missense, nonsense, splicing defects, and deletions 3. CNGB1-related RP is characterized by early-onset night blindness (typically before age 10) but shows long-term retention of central vision despite widespread retinal degeneration, distinguishing it from more aggressive RP forms 34. Recent research demonstrates that CNGB1-associated RP frequently includes olfactory dysfunction, with most affected patients showing reduced or absent smell 24. Gene augmentation therapy using AAV5-delivered CNGB1 has shown promising results in animal models, restoring rod function and retinal structure for at least 12 months, establishing feasibility for clinical development 5.