GATA6 syndrome is a very rare disease with an autosomal dominant inheritance caused by pathogenic heterozygous variants in the GATA6 gene, which is characterized by a combination of diabetes mellitus (predominantly in the neonatal period), exocrine pancreatic insufficiency, and congenital heart and gastrointestinal defects. The gene discussed is GATA6; the disease is exocrine pancreatic insufficiency.