INS and congenital isolated hyperinsulinism: HH can either be due to congenital hyperinsulinism caused by genetic defects (CHI) in key genes regulating insulin secretion or secondary to certain perinatal risk factors (birth asphyxia, intrauterine growth retardation, and maternal diabetes mellitus) or associated with metabolic conditions (congenital disorders of glycosylation, β-oxidation defects).