Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
2827899 | Blood Cells, Molecules, and Diseases | 2010 | 5 Pages |
We describe the molecular and hematological profiles of thalassemia syndromes caused by interactions of hemoglobin (Hb) Q-Thailand [α74(EF3) Asp-His] and various hemoglobinopathies found in 52 unrelated adult Thai subjects. Ten genotypes including several previously undescribed conditions were observed, which were classified into 4 groups. Group I included 26 Hb Q-Thailand heterozygotes and a homozygotous subject. Group II included subjects with Hb Q-Thailand and other α-thalassemia alleles in trans including 1 compound Hb Q-Thailand/α+-thalassemia (− α3.7), 2 Hb Q-Thailand/Hb Constant Spring disease and 6 Hb H/Q-Thailand disease. The average levels of Hb Q-Thailand were found to be 29.8%, 82.3%, 34.7%, 49.2–49.3% and 79.4%, respectively. Both Hbs Bart's and H were observed in addition to Hb Q-Thailand in all 6 cases with Hb Q-H disease but not in a homozygous Hb Q-Thailand. Group III included 7 double heterozygotes for Hb Q-Thailand/Hb E, 3 Hb Q-Thailand/Hb E/α+-thalassemia (−α3.7), 3 heterozygous Hb Q-Thailand/homozygous Hb E and 1 triple heterozygote for Hb Q-Thailand/Hb Constant Spring/Hb E. In this group, Hbs E (αA2βE2), Q-Thailand (αQT2βA2) and QE (αQT2βE2) were observed on both HPLC and capillary electrophoresis. The Hb QE, rather than Hb Q-Thailand, was detected in all 3 cases with heterozygous Hb Q-Thailand and homozygous Hb E. The remaining two cases in group 4 were double heterozygotes for Hb Q-Thailand and β0-thalassemia in which Hb Q-Thailand, elevated Hb A2 (αA2δ2), and Hb QA2 (αQT2δ2) were detected. DNA analysis identified the Hb Q-Thailand mutation (α74: GAC-CAC) and the linked (− α4.2) in all cases. Analysis of α-globin gene haplotype provided the first evidence of a single origin of this Hb variant in Thai population.