The article presents a clinical case of a child with a perinatal form of Niemann–Pick disease type C. The clinical manifestations were cholestasis syndrome, cytolysis, hepatosplenomegaly, muscle hypotension. Differential diagnostics was performed with toxic, cytomegalovirus, viral hepatitis, alpha-1-antitrypsin deficiency, autoimmune liver diseases, aminoacidopathies, Alajille syndrome. After Cholestasis panel genetic testing, a mutation in the NPC1 gene was detected. Biochemical diagnostics showed an increase in the concentration of lysosphingomyelin-509 and increased activity of chitotriosidase in dry blood spots. According to the Sanger sequencing of the NPC1 gene, a nucleotide substitution of chr18:21131617G>A was detected in a child in a homozygous state. According to vital indications (“off-label use”), the patient was prescribed substrate-reducing therapy with Miglustat. Relief of cholestasis syndrome, minimal cytolysis syndrome after administering the drug for 1 month may indicate good tolerability and effectiveness of therapy.