AbstractKabuki syndrome (KS) is a congenital malformation disorder with a spectrum of clinical manifestations involving different organs. Until the identification of MLL2 gene mutation in 2010, the diagnosis was made only clinically by the characteristic facial features with other common and uncommon features. Hypoglycemia, although an uncommon feature in KS, is very important to be recognized, as early diagnosis and appropriate management will reduce further long‐term neurologic morbidity in these patients. We report on four patients with KS presenting with persistent hypoglycemia. Hyperinsulinemic hypoglycemia was the cause of hypoglycemia in two out of four patients and one patient had growth hormone deficiency. The mechanism of the hypoglycemia in one patient is still unclear. Three out of these four patients were found to have mutation in the MLL2 gene. Our observations suggest that patients with KS may have hypoglycemia due to different mechanisms and that MLL2 gene may have a role in glucose physiology. © 2013 Wiley Periodicals, Inc.