LHX3 is a LIM-homeodomain transcription factor essential for pituitary gland and nervous system development 1. It functions as a sequence-specific DNA-binding transcription activator that recognizes the consensus motif 5'-AATTAATTA-3' in target gene regulatory elements, including those of glycoprotein hormone genes and CHX10 2. LHX3 operates through interaction with coactivators, including the INHAT complex components LANP and TAF-1β, which modulate chr9 structure and histone acetylation to regulate pituitary gene transcription 3. The gene produces two functionally distinct isoforms differing in their amino termini but sharing conserved LIM domains and homeodomains 2. Mutations in LHX3 cause combined pituitary hormone deficiency-3 (CPHD3), a rare syndrome characterized by deficits in anterior pituitary hormones and complex nervous system developmental abnormalities 1. Patients exhibit short stature from growth hormone deficiency, metabolic disorders, and reproductive system deficits 1. Emerging evidence demonstrates that LHX3 pathogenic variants also cause progressive sensorineural hearing loss and vestibular impairment, indicating critical roles in inner ear development 4. A tissue-specific enhancer directs LHX3 expression in gonadotrope and thyrotrope cells expressing α-glycoprotein subunits and in V2a interneurons during development 5. Growth hormone replacement therapy effectively addresses the short stature phenotype 1.