Genetic epidemiology of sickle cell anemia and B-thalassemia in Kuwait

ABSTRACT

Mutant beta[s] and alpha-beta- thalassemia alleles are found in polymorphic frequencies in the Arabian peninsula. The precise prevalence figures for Kuwait have, however, not been determined. Using PCR and allelepecific oligonucleotide hybridization techniques, we have characterized the alleles found among Kuwaiti SS, beta-thal major and beta-thal intermedia patients. alpha-Globin gene status was determined among the SS patients and their AS relatives. We have also attempted to identify the ethnic ancestries of the groups in which particular mutations were found. Most of our SS patients [75.9%] are homozygous for the Saudi Arabian/India haplotype, although a few with various combinations of the Benin and Bantu haplotypes are seen, alpha-thal determinants were found in 40% of the individuals studied; the -3.7 kb deletion [alpha-thal-2 trait] was the most common, accounting for 30.0% while non-deletional traits were found in -10%. Ten different beta-thal mutations have been identified so far among Kuwaitis. IVS-II-I[G - A] was the commonest in those of Saudi origin, the IVS-1 3 end 25 bp pair deletion was found only in those of Iranian descent. Only three mutations [the IVS-II-1 [G - A], IVS-I-1 [T-C] and codon 8 [-AA] were found in patients with thalassemia intermedia]. A knowledge of these mutations provides a basis for early and definitive diagnosis and promotes realistic genetic counseling and early institution of appropriate therapeutic measures in our patients