LINS1 (lines homolog 1) is a human homolog of the Drosophila segment polarity gene that encodes an essential regulator of Wingless/Wnt signaling 1. LINS1 functions as a substrate adaptor protein within a tumor suppressor complex with UBR5 (mammalian homolog of Drosophila Hyd), targeting zinc finger proteins for ubiquitin-mediated degradation 2. At the molecular level, LINS1 accumulates in the nucleus to modulate Wnt target gene transcription through association with β-catenin 3, and mutations in LINS1 alter HuR expression during neural differentiation, potentially affecting commissural axonal growth 4. LINS1 mutations cause autosomal recessive intellectual developmental disorder-27 (MRT27) 5, with biallelic variants (nonsense, frameshift, and missense mutations) identified in affected families 67. The clinical phenotype extends beyond intellectual disability to include schizophrenia, anxiety, movement disorders, dysmorphic features, oculomotor abnormalities, dystonia, and cardiac complications 68. Notably, distinct phenotypes correlate with variant location within different LINS1 domains, suggesting genotype-phenotype relationships 1. Brain MRI typically shows nonspecific changes without major malformations 8. LINS1-related disorder represents a rare but clinically heterogeneous neurodevelopmental condition requiring expanded clinical recognition.