Micromapping of Thalassemia and Hemoglobinopathies Among Laos, Khmer, Suay and Yer Ethnic Groups Residing in Lower Northeastern Thailand

Abstract

Northeastern (NE) Thailand is one of the areas with a prevalence of thalassemias and hemoglobinopathies. Data on the prevalence of the diseases in minorities in the region has been limited. This study aimed to survey the thalassemias and hemoglobinopathies that take into account ethnicity. Four ethnic groups, including Laos (n = 162), Khmer (n = 145), Suay (n = 134), and Yer (n = 101) inhabiting the lower region of NE Thailand, were selected to represent the study populations. The results demonstrated that an extremely high prevalence of Hb E (HBB: c.79G>A) (>50.0%) was observed in the Khmer, Suay and Yer ethnic groups. The highest prevalence of α⁺-thalassemia (α⁺-thal) [–α^3.7 (rightward)] deletion was found in the Khmer ethnic group (48.28%). The –α^4.2 (leftward) deletion (α⁺-thal) was restricted to the Yer ethnic group. Yer and Suay had a high incidence of Hb Constant Spring (Hb CS; HBA2: c.427T>C) as well as Hb Paksé (HBA2: c.429A>T). As the prevalence of α⁰-thalassemia (α⁰-thal) is relatively high in Suay (7.46%), couples who are members of Suay ethnic population should be urged to undergo hematological screening before planning a pregnancy to control the Hb Bart’s hydrops fetalis. Micromapping of thalassemias and hemoglobinopathies herein described will be helpful in genetic counseling and public education campaigns, which should be carried out in appropriate languages, with exhibitions at the village levels. This information will be of benefit for the long-term effort to reduce the burden of severe thalassemia disease in the region.

Keywords:

• Ethnic groups
• hemoglobinopathies
• lower northeastern (NE) Thailand

Acknowledgments

We thank all volunteers and staff from the Health Promoting Hospital in Ubon Ratchatani and Sisaket Provinces, NE Thailand. We also thank Dr. Mereerat Manwong (College of Medicine and Public Health, Ubon Ratchathani University, Ubon Ratchathani, Thailand) for helping in the calculation of prevalence and gene frequency and the medical technologists at the Ubon Ratchathani University Hospital, Ubon Ratchathani, Thailand for helping with the laboratory analyses. Miss Roongnalin Bunthupanich is a graduate student at the Biomedical Sciences Program, College of Medicine and Public Health, Ubon Ratchathani University, Ubon Ratchathani, Thailand.

Disclosure statement

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

Additional information

Funding

This study and R. Karnpean were supported by a grant from the Thailand Research Fund (TRF), Office of the Higher Education Commission (OHEC) and Ubon Ratchathani University [Contract ID MRG6180197]. Supan Fucharoen is a recipient of the TRF Research Team Promotion Grant (RTA) of the Thailand Science Research and Innovation (TSRI), Thailand [Contract ID RTA6280005].