Abstract
Kabuki syndrome is a clinically and genetically heterogeneous congenital malformation syndrome with protean clinical manifestations. This reflects the important epigenetic role in embryonic development of the two genes currently known to be associated with Kabuki syndrome i.e., KMT2D and KDM6A, which are responsible for Kabuki syndrome 1 and Kabuki syndrome 2, respectively. Hypoglycemia is thought to be a rare manifestation of Kabuki syndrome; however it may be under diagnosed. Herein we describe the case of a 5-year-old girl with Kabuki syndrome 2 in whom persistent hyperinsulinism was diagnosed at 4 years of age. We postulate an epigenetic mechanism for hyperinsulinism where specific loss KDM6A demethylation of the H3K27me3/me2 mark may lead to deregulated pancreatic ß-cell development.