Abstract
This case study examines a preterm newborn with autosomal recessive ABCC8 gene-related diffuse congenital hyperinsulinism (CHI). The interdisciplinary management of the patient, including advanced genetic testing and long-read sequencing, finally led to the molecular diagnosis. These findings were relevant for the immediate decision on further treatment options highlighting the importance of differentiating between focal and diffuse CHI forms, and for providing the family with counseling on the recurrence risks and prenatal diagnostic options. In summary, this study illustrates the clinical and genetic intricacies of CHI, emphasizing the significance of comprehensive genetic analysis in diagnostics and tailored treatment. The case advocates for the integration of state-of-the-art genetic diagnostic technologies in combination with clinical interdisciplinary management to improve patient outcomes.