In total 155 different variants in SLC16A2 were identified in patients with MCT8 deficiency, representing 63 missense variants, 22 nonsense, 37 frameshift variants, 9 deletions or insertions of 1–3 amino acids, 14 large deletions and 10 splicing variants (Fig. 1C and Supplementary Fig. 3). The gene discussed is SLC16A2; the disease is hyperinsulinemic hypoglycemia, familial, 4.