CNTN5 (contactin 5) is a neural adhesion molecule belonging to the immunoglobulin superfamily that mediates cell-cell interactions during nervous system development 1. The gene maps to chromosome 11-q22.2 1 and exhibits region-specific expression patterns in the adult brain, with highest levels in the amygdala and occipital lobe 1. CNTN5 functions in synaptogenesis, synaptic maturation, and axon guidance, with particular involvement in the auditory pathway 2. The protein promotes neurite outgrowth in cerebral cortical neurons and modulates neuronal plasticity during critical developmental phases 3. CNTN5 has been implicated in neurodevelopmental disorders, particularly autism spectrum disorder (ASD). Neurons deficient for CNTN5 demonstrate consistent spontaneous network hyperactivity, suggesting a role in synaptic dysfunction 4. CNTN5 variants have been identified in ASD patients, and elevated CNTN5 expression is observed in Parkinson's disease-related dopaminergic neuropathy 5. A female-specific genetic variant in CNTN5 (rs10736549) is associated with neuroticism and mood disorders 6. While CNTN5 appears relevant to neuropsychiatric conditions, a recent association study in a Japanese population found limited evidence for rare CNTN5 variants as major contributors to ASD susceptibility 2. CNTN5 remains a candidate gene for neurodevelopmental disorders requiring further investigation 78.