LRRTM1 (leucine-rich repeat transmembrane neuronal 1) is a synaptogenic cell adhesion molecule that mediates excitatory synapse formation at both pre- and postsynaptic levels 1. The protein functions as a trans-synaptic ligand, binding presynaptic neurexins to regulate neurotransmission and synaptic differentiation 1. LRRTM1 is notably an imprinted gene showing maternal suppression, with paternally-inherited genetic variation significantly associated with human handedness and functional cerebral asymmetries, particularly when cognitive control mechanisms are engaged 23. Genetic variation in LRRTM1 demonstrates continuity between clinical schizophrenia and subclinical schizotypy, with risk alleles linked to higher schizotypy levels in nonclinical populations 4. Additionally, epigenetic modifications (methylation) in the LRRTM1 promoter region associate with mixed-handedness development 4. LRRTM1 resides within the seventh intron of CTNNA2, sharing bidirectional promoters that coordinate expression of both genes with differential effects on neuronal connectivity 5. Emerging evidence suggests LRRTM1 expression changes correlate with neurodegenerative processes, including reduced expression in Alzheimer's disease patients 6. The gene represents a candidate locus for understanding molecular mechanisms underlying brain asymmetry, neurodevelopmental disorders, and psychiatric conditions.