Determination of deletional alpha thalassemias by multiplex PCR

α-Thalassemia is an inherited, autosomal recessive disease characterized by microcytic hypochromic anemia. It is one of the most common monogenic gene disorders in the world population. Clinical severity ranges from nearly asymptomatic to mild microcytic hypochromia and a fatal hemolytic condition called Hb Bart Hydrops Fetalis Syndrome. The molecular basis is usually deletions and less often point mutations. The increase in clinical diversity and disease severity is directly related to decreased expression of one, two, three, or four copies of the α-globin genes. Deletions and point mutations in α-globin genes and their regulatory elements have been extensively investigated in carriers and patients, and these studies have provided insight into the regulation of α-globin genes. Looking at naturally occurring deletions and point mutations, our knowledge of the regulation and expression of the globin gene will continue to increase, leading to new therapeutic targets. In this study, we have successfully set up single-tube multiplex PCR assay (gapPCR) that can detect heterozygosity, homozygosity, and compound heterozygosity of four α-globin gene deletions. This simple assay has been used on over one hundered DNA samples (n=112) from α-thalassemia traits (n=110) and HbH disease (n=2) individuals, and represents a rapid and reliable method for detecting 4 of the most common alpha globin gene deletion in our country.