PHKB and hyperinsulinemic hypoglycemia, familial, 4: Through phenotypical analysis, with hepatomegaly (Figure 1C,D), sub-normal level of fasting glucose profile (Figure 2A), and significantly elevated blood ketone levels (Figure 2B), we confirm that Phkb−/− mouse perfectly mimics GSD-IX-beta deficiency and it enabled further investigations to find disease mechanism underlying PHK-beta deficiency.