Beta thalassemic mutations recognized by DNA mapping with Hph I and Rsa I in the Algerian population.

By using Hph I and Rsa I restriction enzymes and beta globin large intervening sequence as a probe, we have investigated the DNA of 20 Algerian patients with beta(0) or beta(+) thalassemia. In any of them, we detected the nucleotide change which is known to generate an additional Hph I site at the 5' splice junction of the beta globin large intervening sequence and which yields a beta(0) phenotype. In one of them, we detected the nucleotide change which is known to generate an additional Rsa I site within the beta globin large intervening sequence and which is supposed to yield a beta(+) phenotype. These results indicate that these two types of mutation are relatively rare in the Algerian population.