Caught by Whole-Exome Sequencing: Hemoglobin Sun Prairie in a Patient With Unexplained Hemolytic Anemia From Nepal

Unstable hemoglobin leading to chronic hemolysis is a rare yet an important cause of hemolytic anemia and can be easily missed if not thought of during evaluation. Hemoglobin Sun Prairie is an extremely rare α-globin mutation associated with hemolytic anemia.

We report a 22-year-old female from Nepal who presented with easy fatigability and jaundice since her childhood with worsening of symptoms for 2 months. Examination revealed pallor, icterus, and splenomegaly. Investigation showed anemia with low mean cell volume (MCV), reticulocytosis, indirect hyperbilirubinemia, and raised lactate dehydrogenase (LDH) level. Workup for etiology of hemolysis, including autoimmune, nutritional, RBC enzyme deficiency, and osmotic fragility, was negative. Hemoglobin electrophoresis was inconclusive. Whole-exome sequencing identified a pathogenic mutation in HBA2 gene, confirming Hemoglobin Sun Prairie. To our knowledge, this represents the first reported case of Hemoglobin Sun Prairie from Nepal.

This case highlights the importance of genetic testing in an unexplained hemolytic anemia. Genetic testing such as whole-exome sequencing would help in the early identification of rare causes of hemolytic anemia which can guide in the genetic counseling and prevent unnecessary investigations and interventions.