AHDC1 (AT-hook DNA binding motif containing 1), also known as Gibbin, is a transcription factor essential for early epithelial morphogenesis and skin development 1. The protein directly binds promoter and enhancer regions to maintain local enhancer-promoter chr1 architecture 1. AHDC1 interacts with sequence-specific zinc-finger transcription factors and methyl-CpG-binding proteins to regulate mesoderm gene expression, enabling proper dermal-epidermal signaling and keratinocyte stratification 1. Loss of AHDC1 function increases DNA methylation at mesodermal genes, disrupting ectoderm-mesoderm patterning and resulting in defective epidermal stratification 1. Clinically, AHDC1 mutations cause Xia-Gibbs syndrome (XGS), a rare neurodevelopmental disorder characterized by intellectual disability, developmental delay, hypotonia, and speech impairment 23. Recent studies reveal broader physiological roles: AHDC1 deficiency causes obesity with reduced energy expenditure, insulin resistance, and metabolic dysfunction 4. Emerging evidence suggests genotype-phenotype correlations, with N-terminal variants associated with developmental regression and other variants linked to epilepsy and scoliosis 2. Novel associations include musculoskeletal abnormalities and genital/gonadal alterations, indicating multisystem involvement beyond neurodevelopmental deficits 2. AHDC1 has been reclassified from a Tdark to Tbio gene, reflecting increasing recognition of its biological and clinical significance 5.