Epidemiology of thalassemia among the hill tribe population in Thailand

Abstract

Background Thalassemia is a severe disease that occurs due to abnormalities in hemoglobin genes. Various genetic factors in different populations lead to different clinical manifestations of thalassemia disease, particularly among people who have a long history of migration and who have married among tribes, such as the hill tribe people in Thailand. This genetic epidemiological study aimed to estimate the prevalence of various forms of thalassemia among the six main hill tribe populations in Thailand. Methods A cross-sectional study was conducted to obtain information and blood specimens from school children belonging to one of the six main hill tribes in Thailand: Akha, Lau, Hmong, Yao, Karen, and Lisu. Hill tribe children who were attending grades 4–6 in 13 selected schools in Chiang Rai Province, Thailand, were invited to participate in the study. A validated questionnaire and 3 mL blood specimens were collected after obtaining information consent forms from both the children and their parents on a voluntary basis. A complete blood count (CBC) was performed, followed by osmotic fragility (OF) and dichlorophenol indophenol precipitation (DCIP) tests to screen for thalassemia. High-performance liquid chromatography (HPLC) and real-time quantitative polymerase chain reaction (qPCR) were used to identify hemoglobin type and α-thalassemia, respectively. A t-test, chi-square and logistic regression were used to detect the associations between variables at the significance level of α = 0.05. Results A total of 1,200 participants from 6 different tribes were recruited for the study; 50.0% were males, and 67.3% were aged 11–12 years. The overall prevalence of thalassemia carriers according to the screening tests was 9.8% (117 of 1,200). Among the cases, 83 were A2A (59 cases were α-thalassemia 1 carrier or α-thalassemia 2 carrier or homozygous α-thalassemia 2, and 24 cases were β-thalassemia trait with or without α-thalassemia); 1 case was EE (homozygous Hb E with or without α-thalassemia); 31 cases were EA (30 cases were the Hb E trait, and 1 case was Hb E trait with or without α-thalassemia); 1 case was A2A Bart’s H (Hb H disease α-thalassemia 1/α-thalassemia 2); and 1 case was A2A with abnormal Hb. The prevalence of the α-thalassemia 1 trait among the hill tribe population was 2.5%. The greatest prevalence of the α-thalassemia 1 trait was found in the Karen (3.0%) and Hmong (3.0%) tribes. Conclusions The prevalence of some forms of thalassemia in the hill tribe population is higher than that in the Thai and other populations. Effective and available thalassemia screening tests, including essential information to protect the next generation through the specific counseling clinic, are crucial, particularly due to increasing marriages within these populations.

Association between Haematological Parameters and Exposure to a Mixture of Organophosphate and Neonicotinoid Insecticides among Male Farmworkers in Northern Thailand

“…Moreover, exposure to THX elevates the NEU-to-LYM and NEU-to-leukocyte ratios, while exposure to CLO causes anaemia in frogs, suggesting that exposure to high concentrations of CLO and THX exerts haematotoxic effects [23]. Another possible explanation for the decreases in Hb, MCH and MCHC is the thalassemia trait in our study population due to the high prevalence of thalassemia in hill tribes in Southeast Asia, notably northern Thailand [76,77].…”

Cell and Gene Therapy for Anemia: Hematopoietic Stem Cells and Gene Editing

“…In the Eastern Mediterranean region, the number of infants born with β-thalassemia each year is the highest in Pakistan [104]. In Thailand, the overall prevalence of thalassemia carriers among six main hill tribe populations was 9.8% (117 of 1200) [105].…”

Drivers, facilitators, and sources of stigma among Akha and Lahu hill tribe people who used methamphetamine in Thailand: a qualitative approach

“…These people have their own language, culture, and lifestyle [ 22 ]. There are six major groups: Akha, Lahu, Hmong, Yao, Karen, and Lisu [ 23 ]. Akha and Lahu are the first and second largest populations among the hill tribes [ 23 ].…”

“…There are six major groups: Akha, Lahu, Hmong, Yao, Karen, and Lisu [ 23 ]. Akha and Lahu are the first and second largest populations among the hill tribes [ 23 ]. Even though they have been living in Thailand for a long time, approximately 30% of them have not been granted Thai citizenship, which would give them a 13-digit identification card [ 24 ] used to access all public services, including education and health care systems [ 24 ].…”