Hb Sun Prairie: A rare cause of chronic hemolysis in an Indian patient

Haemolytic anaemia is a commonly encountered condition in clinical haematology practise. Dissecting the aetiology of haemolytic anaemia is of paramount importance for appropriate management. We describe a 29-years-old lady of Indian origin, who presented with fatigue and recurrent jaundice for 2 years. Examination revealed pallor, mild icterus, and splenomegaly. Blood tests showed anaemia, reticulocytosis, indirecthyperbilirubinemia, and high serum lactate dehydrogenase, consistent with haemolytic anaemia. Peripheral smear showed severely microcytic hypochromic red cells and polychromasia. Heinz bodies and inclusion bodies were seen with supravital staining. Haemoglobin high pressure liquid chromatography showed low HbA2 and normal HbF. Work-up for iron deficiency was negative. Polymerase chain reaction of the genomic DNA failed to identify common deletions in the HBA genes. Sangers sequencing of HBA2 gene revealed a homozygous missense mutation NM_000517.6: c.391G > C (p.Ala131Pro) leading to a highly unstable hemoglobin, Hb Sun Prairie. Mother was heterozygous for the same mutation, and father was unavailable for genetic testing. We highlight the role of sangers sequencing in unravelling the underlying aetiology of haemolytic anaemia. Pathophysiology and existing literature of Hb Sun Prairie has been discussed.