Occurrence of the – –^SEA, – –^THAI and – –^FILα-Thalassemia-1 Carriers from a 7-Year Study at Ramathibodi Hospital, Bangkok, Thailand

Abstract

α-Thalassemia (α-thal) is one of the most common genetic diseases in Thailand. Homozygosity of α-thal-1 (– –/– –) and compound heterozygosity of α-thal-1/α-thal-2 (– –/–α) leads to Hb Bart's (γ4) hydrops fetalis and Hb H (β4) disease, respectively. In order to better control and provide prevention of α-thal disease, the prevalence of α-thal-1 carriers and the types of genotypes in the Thai population should be known. A 7-year retrospective study, employing multiplex gap-polymerase chain reaction (gap-PCR) of 31,632 blood samples from Ramathibodi Hospital, Mahidol University, Bangkok, revealed an α-thal-1 carrier rate of 14.40% with the – –^SEA (NG_000006.1: g.26264_45564del19301), – –^THAI (NG_000006.1: g.10664_44164del33501) and – –^FIL (NG_000006.1: g.11684_43534del31851) genotypes, constituting frequencies of 14.21, 0.18 and 0.01%, respectively. Although the – –^FIL genotype is rare in the Thailand, its detection should be included in future α-thal screening programs.

Keywords:

• α-Thalassemia-1 (α-thal-1)
• – –^FIL deletion
• polymerase chain reaction (PCR)
• – –^SEA deletion
• – –^THAI deletion

Acknowledgements

The authors thank Professor Prapon Wilairat (Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand) for critical reading of the manuscript.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.