Association of polymorphic pattern of the (AT) × (T)y motif of β-globin gene in North Indian thalassemia patients with variable clinical expression.

Among the polymorphic genetic markers of the β-globin gene cluster, the (AT) × (T)y motif and a common C→T variation at -158 of the Gγ globin gene were investigate din 20 β-thalassemia IVSI-5 (G→C) homozygous patients with variable clinical manifestation and 10 normal subjects from north India to deduce any association with the co-inherited genetic polymorphism. We found (AT)(7)(T)(7) repeat motif in all the 20 chromosomes of normal subjects and two different sequence configuration(AT)(8)(T)(5), (AT)(9)(T)(5) in the patient group whereas the presence of -158(C→T) Gγ was quite polymorphic. We conclude that polymorphism -158(C→T) Gγ and (AT) × (T)y sequence variation other than (AT)(7)(T)(7) could influence the phenotype by increasing Hb F expression.