KCNJ11 and neonatal diabetes mellitus: While cohort studies in Europe, Japan and the United States have reported de novo variants in KCNJ11 as the most common cause of permanent neonatal diabetes mellitus (PNDM),4, 7, 8, 9, 10, 11, 12 in countries with a high rate of consanguineous marriages, the inheritance pattern of PNDM is very different.