Interaction between hereditary spherocytosis and the beta-thalassemia trait: A case report.

Coinheritance of hereditary spherocytosis (HS) and b thalassemia is very rare. HS is a familial haemolytic disorder resulting from primary abnormality of red cell membrane. It is transmitted as an autosomal dominant trait. b thalassemia is also a common inherited disorder. In Indians, the frequency of b thalassemia is reported between 3.5&14.9% [1]. The haemolytic anemia resulting from their coexistence has been shown to be of variable severity in different studies [2-5]. We hereby present a case of a 50 yr old Nepalese female who came with fever, cough & weakness without any organomegaly. CBC findings revealed microcytic hypochromic red cells with high red cell count (>5x106/μl) and mildly increased RDW suggestive of bTT (Table 1). Peripheral smear showed large number of microspherocytes, microcytic hypochromic cells, target cells and occasional red cells with basophilic stippling (Figure 1). Reticulocyte count was 1.5%. Direct Coomb’s test was negative and serum bilirubin was normal (1.2 g/dl). HPLC of Hb revealed an increased Hb A2 (4.8%) and Hb F (6.0%). Her son revealed very few spherocytes in peripheral smear and CBC findings were suggestive of bTT. Coomb’s test was negative, Hb HPLC showed high HbA2 (5.1%). The incubated osmotic fragility curves of both the patient and her son were shifted to right with a tail of fragile cells. Thus, a diagnosis of HS with bTT was made in both (Figure 2). Inheritance of HS has been reported in association with α thalassemia, b thalassemia and certain enzyme deficiencies [2-8]. The results are conflicting regarding the degree of hemolysis, when hereditary spherocytosis and