Beta globin gene haplotypes in Bahraini patients with sickle cell anemia

Molecular genetic studies were undertaken to determine the haplotype of chromosomes carrying the sickle cell allele in Bahraini patients, and hence allow consideration of the possible source of these alleles. A total of 59 individuals form 19 families were studied. Of these, 35 were affected with sickle cell anaemia, and 24 were carriers. Haplotypes were investigated by PCR amplification of globin target sequences followed by restriction digestion using HindIII, AvaII, HindII, and HinfI polymorphism. In the 19 families the Bs gene was found to be linked to the haplotypes +++++- [also known as the Asian haplotype] in 33 chromosomes [90%], to the haplotype +-+-++ known as the S2 haplotype in 2 chromosome [5%], the haplotype S1 [-++++] in one chromosome [2.5%], and to the haplotype --+--+ found in association with beta thalassaemia in one family [2.5%]. Our study shows that the Asian haplotype is predominant in Bahrain [90%]. This haplotype has previously been found to be linked to a benign sickle cell anaemia. The African haplotype S1 was found in one family only

Determination of G /A +G ratio in beta thalassemia, an indicator of diseases severity

The globin chains were separated by electrophoresis on acrylamide-bis acrylamide gels containing Triton X-100, urea, 2 mercaptoethanol, and acetic acid. The G gamma/ A gamma+ G gamma ratio was determined in 25 cord blood samples and in 46 beta-thalassemic homozygotes among Iranian children. In 25 cord blood samples the mean value for G gamma / ? gamma + G gamma was 0.66. All beta-thalassemia homozygotes had an elevated HbF from 5-80% and the mean value for G gamma / G gamma + A gamma was 0.64 and their G gamma chain level in the peripheral blood was found to be intermediate between the embryonic and adult values. We conclude that HbF and G gamma chain level as well as the severity of the disease is due to Beta-thalassemia variants, but there is a poor correlation between HbF level and G gamma /G gamma + ? gamma ratio, both in cord blood samples and Beta-thalassemia samples