Wolcott-Rallison syndrome is a rare autosomal recessive disease characterized by neonatal diabetes mellitus in combination with osteodysplasia and liver failure. This disease is the most common cause of neonatal diabetes mellitus in consanguineous families. Wolcott-Rallison syndrome is associated with mutations in the EIF2AK3, the gene encoding a transmembrane enzyme PERK (pancreatic endoplasmic reticulum kinase) which inhibits the synthesis of proteins in the event of misfolding in the endoplasmic reticulum. In addition to the core symptoms patients may develop multisystemic clinical manifestation including acute renal and liver failure, short stature, exocrine pancreatic insufficiency, neuro-motor deficit, hypothyroidism, anemia, neutropenia, recurrent hypoglycemia. The disease is characterized by high mortality, more than 50% of patients die from fulminant liver failure. The awareness of Wolcott-Rallison syndrome is extremely low due to the rarity of detection, however in view of the severity of the disease and the unfavorable prognosis patients with this syndrome require timely diagnosis and care of well-organized team of specialists.

Congenital hyperinsulinism (CHI) is caused by insulin hyperproduction by β-pancreatic cells. CHI is associated with high risk of complications of chronic hypoglycemia, and therefore timely diagnosis of the disease and immediate initiation of therapy is a top-priority task. The choice of treatment tactics largely depends on the morphological form of the disease. Morphological form cannot be established based on clinical and laboratory presentation of the disease, ultrasound, MRI, computed and positron emission tomography (PET) with [18F]-fluorodeoxyglucose. Calcium stimulation test and percutaneous transhepatic blood sampling from the portal vein were previously used for differential diagnosis, but the results provided by these invasive studies are imprecise. At present, preoperative differential diagnosis of diffuse and focal forms of CHI is based on the data of genetic testing and radionuclide diagnosis ([18F]-DOPA PET). The article presents the first results of the use of [18F]-DOPA PET in CHI patients in the Russian Federation. Radionuclide study was performed in 17 patients with pharmacoresistant CHI followed by comparative analysis of the results of 18F-FDG PET/CT and histological picture of intraoperative pancreatic tissue samples, which is known as the gold standard for the differential diagnosis of HI histological forms.