Genotype Phenotype Correlation in Thalassemia Syndromes and Their Correlation with Xmn-1 Polymorphism.

Among the inherited disorders of blood, thalassemia constitutes a major bulk of genetic diseases in India. It causes a high degree of morbidity. In a study conducted in India it has been estimated that there is a frequency of 1:2700 at the time of birth. Thus on an average 9000 new thalassemics are born every year in India.. The present study has been aimed at investigating the clinical and hematological spectrum in the above syndrome. It also assessed the prevalence of Xmn -1 polymorphism its relationship with various mutations and its role in modifying the clinical manifestations. The study was conducted on fifty patients representing 49 families and consisting of 33 males and 17 females who were homozygous for beta thalassemia and ranged in age from 3 months to 32 years. The patients were screened for common Indian mutations and their Xmn polymorphism status and this was correlated with their clinical parameters. Apositive correlation in presence of Xmn-1 polymorphism and IVS1-1 mutation was noted. There was also a correlation between age at diagnosis and also the age at first transfusion. There was a correlation between Xmn polymorphism and IVS1-1 mutation. This was found most commonly in the Punjabi Khatri community. None of the patients with blood group O had positivity of Xmn polymorphism. There was no correlation between Xmn and hemoglobin at diagnosis, HbF at diagnosis, MCV at diagnosis, amount of blood in mL/Kg/year and sex and religion.