A Japanese neonatal case of glucose-6-phosphate dehydrogenase deficiency presenting as severe jaundice and hemolytic anemia without apparent trigger

BACKGROUND Glucose-6-phosphate dehydrogenase (G6PD) deficiency is rare among Japanese ethnicity although it is known as one of the most common hereditary disorders of erythrocytes, causing intravascular hemolysis. It is well-known that G6PD deficiency may cause hemolysis even in the neonatal period. However, most cases are asymptomatic, and the frequency of severe anemia is low. FINDINGS We describe a Japanese male neonatal case of G6PD deficiency presenting as severe, persistent indirect hyperbilirubinemia on day 2 and hemolytic anemia. He was born to non-consanguineous Japanese parents without any family history. We could not find any triggers that could have induced hemolysis during pregnancy. CONCLUSIONS This case encouraged us to investigate G6PD deficiency as a differential diagnosis of severe neonatal jaundice and hemolytic anemia despite the low prevalence in Japan.