Detection of common deletional α‐thalassemia‐2 determinants by PCR

Abstract

We have developed a rapid approach to detect the two most common alpha-thalassemia-2 (alpha-thal-2) determinants by the polymerase chain reaction (PCR) technique, which takes a few hours to complete. Specific oligonucleotides selectively amplify appropriate segments of the chromosome with the deletion and the normal chromosome under identical experimental conditions, and the products are identified by electrophoresis on 1.5% agarose. Characterization of the two most prevalent types of the -alpha 3.7 determinant [-alpha 3.7(I) and -alpha 3.7(II)] can be made by Apa I digestion of the PCR product. Two types of alpha-thal-2 determinants, -alpha 3.7 and -alpha 4.2, were tested in numerous samples from various parts of the world. This approach is believed to provide a cost-effective way to screen large numbers of blood samples in a relatively short time and can be used to identify alpha-thal-2 heterozygotes and homozygotes and compound heterozygotes (-alpha 3.7/-alpha 4.2) in populations where such alpha-gene defects are shown to exist at high frequencies.

Temporal sequence of splenic dysfunction in sickle cell disease

“…DNA was isolated from peripheral leukocytes with the method of Poncz et al [19]. All the SS patients were screened for the presence of a-thal-2 (À3.7 kb) deletion that is the commonest cause of a-thal trait in this community [20]. The b Sglobin gene cluster haplotypes were determined using allele-speci®c oligonucleotide hybridization to identify haplotype-speci®c mutations in the 5¢¯anking and IVS-II regions of the G c-and A c-globin genes as previously described [6,21].…”

Spectrum of β thalassemia mutations and HbF levels in the heterozygous Moroccan population

“…The configuration of (AT) x T y alleles was determined by direct sequencing using the ABI Prism Big Dye technology from Applied Biosystems. Structural analysis of ␣ globin genes was performed by DNA amplification [20,21] for the most frequent ␣ globin gene deletions in the Mediterranean population (␣ 3.7 and ␣ 4.2kb ) [22]. Absence of promoter mutations at A␥ globin gene was ascertained by DNA amplification and sequencing with primers R159-(5ЈTGAAACTGTG-GTCTTTATGAAAATTG3Ј) and R161-(5ЈTGGCGTC-TGGACTAGGAGCTTATT3Ј) and at ␦ globin gene with R117 (5ЈGGGCAAGTTAAGGGAATA3Ј) and R119 (5ЈGGAGAAGAGCAGGTAGGT3Ј), [23].…”

An investigation of the protective effect of alpha+‐thalassaemia against severe Plasmodium falciparum amongst children in Kumasi, Ghana

“…The -PCR-based testing is more rapid, less expensive, safer (no radioactivity involved), more sensitive, and easier to interpret than Southern blot analysis (Bowden et al, 1992, Dode et al, 1993, Baysal & Huisman, 1994, OronJarni et al, 1998. For various reasons, this test has not found its way into routine use but can be used to diagnose thalassaemia, and to determine carrier status.…”