KCNJ11 and neonatal diabetes mellitus: NDM is characterized by the development of hyperglycemia within the first 6 months of life, beta-cell destruction, pancreatic hypoplasia or aplasia, impaired beta-cell function or severe insulin resistance resulting from impaired insulin secretion caused by gain-of-function mutations in KCNJ11 and/or ABCC8 subunits of the KATP channel, which can be divided into two transient diabetes mellitus (TNDM) and perma-nent diabetes mellitus (PNDM) clinical subtypes, depending on the length of the disease course (Cao et al., 2020; Dahl and Kumar, 2020; Pipatpolkai et al., 2020; Horita et al., 2021).