A Mismatched-Primer Polymerase Chain Reaction-Restriction Fragment Length Polymorphism Strategy for Rapid Screening of the Polyadenylation Signal Mutation αT-saudi(AATAAA→AATAAG) in the α2-Globin Gene

The most common nondeletional alpha-thalassemia allele, namely alpha(T-Saudi) (AATAAA-->AATAAG), in the Arabian peninsula and neighboring countries is responsible for a number of cases of Hb H disease. It is expected to alter significantly the clinical manifestations of beta-thalassemia and sickle cell disease, also quite prevalent in these regions. Recognition of the alpha(T-Saudi) allele has so far relied on technically-demanding procedures. Here we report a simple, rapid, and robust polymerase chain reaction-based detection procedure for this allele. This involves priming of the polymerase chain reaction with a deliberately introduced mismatch in one of the primers so that the mutant allele, after amplification, would introduce a StuI restriction enzyme site, the presence of which can be recognized by digesting the polymerase chain reaction product with this enzyme.