In the first patient, del/dup copy number variation (CNV) analysis using the Blueprint Genetics (BpG) Hypoglycemia, Hyperinsulinism and Ketone Metabolism Panel identified a homozygous deletion, ABCC8 c.(2390+1_2391-1)_(3329+1_3330-1)del, encompassing exons 20–26 of ABCC8. Here, ABCC8 is linked to hyperinsulinism.