SK, Md HabibullahNaj, Mohsina2025-10-132025-10-132024https://hdl.handle.net/20.500.14572/2643Md Habibullah Sk Neonatologist, DM Neonatology, Senior Resident, Department of Neonatology, Institute of Post Graduate Medical Education & Research and SSKM Hospital, 244, A J C Bose Road, Kolkata-700020, India Mohsina Naj Paediatrician, Post Doctoral Trainee, Department of Nephrology, Institute of Post Graduate Medical Education & Research and SSKM Hospital, 244, A J C Bose Road, Kolkata-700020, IndiaAbstract: Coffin-Siris syndrome (CSS), a rare BAFopathy, is characterized by developmental delay, dysmorphic features, and variable anomalies. We report a 12-year-old boy with a novel ARID1A truncating mutation presenting with global developmental delay, facial dysmorphism, single kidney, and steroid-resistant nephrotic syndrome (SRNS). Genetic analysis confirmed a heterozygous p.Glu1017Ter mutation in ARID1A. This report expands the phenotypic spectrum of CSS by highlighting its association with glomerular disease, a previously unreported feature.en-USCoffin-Siris syndromeARID1ASteroid-resistant nephrotic syndromeSingle kidneyDevelopmental delayArticle