Molecular genetic studies were undertaken to determine the haplotype of chromosomes carrying the sickle cell allele in Bahrain 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 haplotype + + + + +- (also known as the Asian haplotype) in 33 chromosomes (90%), to the haplotype +-+-++ known as the S2 haplotype in 2 chromosome (5%), to haplotype S1 (-++++) in one chromosome (2.5%), and to the haplotype - - + - - + found in association with beta thalassaemia in one family (2.5%).