Challenging diagnosis of spherocytosis in early infancy.

This case report describes an infant who presented to the emergency department with rhinorrhoea and severe mucocutaneous pallor. Laboratory evaluation revealed normocytic anaemia with reticulocytosis and a peripheral blood smear suggestive of peripheral red blood cell (RBC) destruction, although without the presence of spherocytes. Despite the absence of spherocytes on the peripheral blood smear, the clinical evaluation, including family history, led to the consideration of hereditary spherocytosis (HS). The diagnosis was confirmed through genetic testing, revealing a heterozygous pathogenic variant in the ANK1 gene, associated with HS. This case underscores the diagnostic challenges of HS, particularly in the early infancy, and highlights the importance of genetic panels in cases of unexplained haemolytic anaemia.