PDX1 and neonatal diabetes mellitus: Biallelic PDX1 variants are a rare genetic cause of NDM, with 17 cases reported worldwide.3, 12 Initially, recessive loss-of-function PDX1 variants were identified as a cause of pancreatic agenesis without extrapancreatic features in three unrelated families.8, 10 Later studies expanded the pancreatic phenotype to include NDM with or without subclinical exocrine insufficiency.3 6 Recent reports have described extrapancreatic features in three unrelated cases with homozygous PDX1 variants,4 5 7 highlighting the need to comprehensively assess the clinical phenotype caused by these variants.