GJA8 encodes connexin 50 (Cx50), a structural component of eye lens gap junctions that forms dodecameric channels connecting adjacent cells 12. These gap junction channels facilitate diffusion of small molecules and ions between lens cells, maintaining cellular homeostasis critical for lens transparency 3. Cx50 is highly expressed in lens fiber cells and epithelial cells, where it functions as part of a functional syncytium essential for normal lens development 4. GJA8 mutations cause congenital cataracts through diverse pathogenic mechanisms 5. Missense variants can disrupt hemichannel formation, leading to decreased reactive oxygen species scavenging, unfolded protein response activation, and cell apoptosis 6. Different mutations exhibit distinct trafficking defects—some show delayed degradation, others accelerated degradation through dysregulated autophagy—all preventing functional hemichannel and gap junction assembly 5. Beyond cataracts, GJA8 variants associate with severe developmental eye anomalies including aphakia, microphthalmia, and sclerocornea, with specific genotype-phenotype correlations identified 7. Additionally, elevated GJA8 expression in the retina contributes to visual development recovery following sensory deprivation 8. GJA8 mutations represent an important genetic cause of congenital eye disease, with implications for molecular therapy development.