Based on the results of whole-exome sequencing, TCGA molecular classification was assigned as follows: case 1 was categorized as copy number high due to the presence of a TP53 mutation; case 2 was classified as microsatellite instability-high (MSI-H) based on mismatch repair deficiency (MMRd); and case 3 was assigned to the POLE ultramutated subgroup due to the detection of a POLE mutation. This evidence concerns the gene TP53 and hyperinsulinemic hypoglycemia, familial, 4.