GCK and hyperinsulinemic hypoglycemia, familial, 4: A number of syndromic and genetic constellations, such as Wolcott−Rallison syndrome (autosomal recessive), immune dysregulation, polyendocrinopathy, enteropathy, X−linked (IPEX) syndrome (X−linked, recessive), phosphoribosyl−ATP pyrophosphate hyperactivity (X−linked), and glucokinase deficiency (MODY2) have been reported in PNDM (2, 4).