Background: To determine the prevalence of Xmn1-(G)γ polymorphism in North Indian children and adolescents with β thalassemia intermedia (TI) and to correlate it with disease severity.
Methods: All patients of thalassemia intermedia presenting to the pediatric hematology clinic of a tertiary care hospital in North India were enrolled. Clinical severity of their disease was assessed by a phenotypic score proposed by Phadke and Agarwal. They were classified according to status of their Xmn1-(G)γ polymorphism as Xmn1-(G)γ +/+, Xmn1-(G)γ +/-, and Xmn1-(G)γ -/- by molecular analysis.
Results: A total of 104 patients were enrolled. Severe TI was seen in 56.7% (59) patients, while 43.3% (45) had non-severe TI. Jaundice was more frequent in severe TI than in non-severe TI. Xmn1-(G)γ +/+ was present in 25.9% (25) patients. The frequency of the Xmn1-(G)γ +/- and Xmn1-(G)γ -/- was 22% and 37.3% in severe TI children. The corresponding frequencies were 31.1% and 42.2% in non-severe TI group respectively. No significant correlation was observed between the Xmn1-(G)γ polymorphism and severity of thalassemia, age at onset of symptoms, age at diagnosis, age at first transfusion, transfusion frequency or average hemoglobin levels. HbF level was significantly higher in Xmn1-(G)γ +/+ and Xmn1-(G)γ +/- patients.
Conclusions: This study showed that although the prevalence of Xmn1-(G)γ polymorphism is high in β thalassemia intermedia patients, it alone could not predict clinical severity in TI patients. Further refinement and validation of clinical scoring system is necessary for guiding appropriate management.
Copyright © 2011 Wiley-Liss, Inc.