Congenital hyperinsulinism: from molecular genetics to clinical practice

Abstract

Persistent hypoglycemia in the neonatal period is a serious metabolic disorder that can cause seizures, coma, permanent brain damage and death. The main cause of hyperinsulinemic hypoglycemia in newborns is endogenous transient and congenital hyperinsulinism. Transitory forms can be associated with maternal factors, genetic syndromes and perinatal stress (asphyxia, maternal toxemia, intrauterine growth retardation, prematurity). The most severe forms of persistent hypoglycemia in infants include congenital hyperinsulinism (CHI). Recent progress in genetics has led to understanding of relations between CHI and the mutations in genes that play key roles in insulin secretion regulating. The most common mutations are defects in ATP­dependent potassium channels (KATP channels) genes. KATP channels are the link between intracellular glucose metabolism, membrane potential of islet cells and insulin secretion. They are the target for the drugs for hyperinsulinism treatment. Other monogenic forms of CHI include mutations of genes involved in intracellular glucose metabolism, ATP synthesis regulation and transcription factors. There are two main histological forms of CHI: diffuse and focal. The article presents diagnostic and treatment algorithm for CHI. The first­line drug for the treatment of all types of CHI is diazoxide. It is effective in all forms of CHI with intact KATP channels. Octreotide (a synthetic analog of somatostatin) is a second­line drug for therapy of CHI. The article presents new drugs for the treatment of CHI: sirolimus and glucagon­like peptide­1 antagonists.