Northern Thais Research Articles

Application of a simplified PCR-SSP method to detect A4GALT*01 and A4GALT*02 typing among Thai blood donors.

An intronic A4GALT single nucleotide variant, rs5751348:G>T, P2 or A4GALT*02 allele has a lower level of the enzyme-encoding A4GALT transcripts than the P1 individuals. Here, we first develop and validate a simple inhouse PCR-SSP method to detect A4GALT*01 and A4GALT*02 alleles, and second, apply this method to compare the allele frequencies between Thai and other populations. The conventional test tube technique was used to detect the P1 antigen in 222 blood samples from Thai blood donors at Thammasat University Hospital. A PCR-SSP method was optimized and validated for reproducibility and specificity to identify these alleles and was subsequently tested on 1,840 DNA samples of unknown phenotypes obtained from central, northern and southern Thais. In addition, allele frequencies of central Thais were compared with those of other populations. In the tested cohort (n=222), P1 and P2 phenotypes were typed in 26.13 and 73.87% of donors, respectively. The developed PCR-SSP was successfully optimized, and the outcomes were consistent with those of serological phenotyping and DNA sequencing results, demonstrating its validity for predicting P1/P2 phenotype. For central, northern and southern Thais, the A4GALT*01 frequency was 0.1579 (430/2,724), 0.1183 (71/600), and 0.2575 (206/800), whereas the A4GALT*02 frequency was 0.8421 (2,294/2,724), 0.8817 (529/600), and 0.7425 (594/800), respectively. Their observed frequencies among central Thais significantly differed from those in other populations (p<0.05). Our study has successfully developed a simple, precise, and reliable method to genotype A4GALT*01 and A4GALT*02 using inhouse developed PCR-SSP for predicting P1/P2 status.

Turbaned Northern Thai-ness: selective transnationalism, situational ethnicity and local cultural intimacy among Chiang Mai Punjabis

ABSTRACT Chiang Mai is home to approximately 400 diasporic Punjabis, some of whom are sixth-generation residents of Thailand. While their transnational orientation, distinct sartorial choices and cultural practices might present them as outsiders to essential Thainess, Northern Thai Punjabis transgress the national image of Thainess and subjectively consider themselves to be Northern (Lanna) Thais. At the same time, these Thai citizens avail themselves of Overseas Citizenship of India (OCI) status for privileged access to economic, cultural and educational resources in India. Based on 51 in-depth interviews and 17 focus group studies among resident Hindu, Sikh and Namdhari Sikh communities in Northern Thailand, this research explores family histories, selective transnationalism, and regional Lanna identities among these overseas Punjabis. As this article will argue, while Punjabi Thais maintain their networks and cultural connections with an historic ancestral homeland, they also cultivate forms of local cultural intimacy in ways which leapfrog the linguistic and cultural hegemony of Thai national identity.

Genotyping Approach to Predict Coa and Cob Antigens in Thai Blood Donor Populations.

Coa and Cob antigens of the Colton (CO) blood group system are implicated in acute and delayed hemolytic transfusion reactions (HTRs). Owing to the inadequate supply of specific antiserum, data on CO phenotypes remain limited. This study aimed to develop genotyping methods to predict Coa and Cob antigens and to estimate transfusion-induced alloimmunization risks in three Thai blood donor populations. The study included 2451 blood samples from unrelated healthy Thai blood donors obtained from central, northern, and southern Thailand. DNA sequencing was used to determine the CO*A and CO*B alleles. In-house PCR with sequence-specific primers (PCR-SSP) and high-resolution melting curve (HRM) assays were performed and genotyping results were compared using DNA sequencing. CO*A and CO*B allele frequencies among Thais were determined using PCR-SSP and their frequencies were compared with other populations. The risks of Coa and Cob transfusion-induced alloimmunization among Thai donor populations were calculated. The validated genotyping results by PCR-SSP and HRM assays agreed with DNA sequencing. The CO*A/CO*A was the most common (100.0, 100.0, and 99.3%), followed by CO*A/CO*B (0.0, 0.0, and 0.7%) among central, northern and southern Thais. Homozygous CO*B/CO*B was not found. The CO*A and CO*B allele frequencies among central Thais significantly differed compared among southern Thais (p < 0.01) but not among northern Thais. Those allele frequencies among Thais were similar to those of Taiwanese, Chinese and Malay-Malaysian populations but not to South Asian, Southeast Asian, Korean, Japanese, Filipino, French Basque, and Maltese populations (p < 0.01). A higher risk of anti-Cob production rather than anti-Coa production was particularly noted in the southern Thai population. This study constitutes the first to determine CO*A and CO*B genotypes using PCR-SSP and HRM assays among Thais and this finding would be beneficial in predicting alloimmunization risk and providing safe transfusions among Thais.

FREQUENCIES OF PREDICTED MIA ANTIGEN AMONG SOUTHERN THAI BLOOD DONORS

Background: The Mia antigen (MNS7) of the MNS blood group system is clinically important in Asian populations. Anti-Mia has been implicated in hemolytic transfusion reactions and hemolytic disease of the fetus and newborn in Thai populations. However, data of this antigen frequency among southern Thais remains unknown.&#x0D; Objective: This study aimed to determine and predict Mia antigen frequencies among southern Thai blood donors and to estimate the risk of alloimmunization among Thais.&#x0D; Methods: A cross-sectional study was conducted. Altogether, 400 southern and 500 central Thai blood samples were genotyped for GYP(B-A-B) and GYP(A-B-A) MNS hybrids using polymerase chain reaction with sequence-specific primer (PCR-SSP).&#x0D; Results: Among them, 19 of 400 (4.45%), and 28 of 500 (9.33%) were positive with the set of GP. Hut, GP.HF, GP.Mur, GP.Hop, and GP.Bun. No GP.Vw phenotype was found among southern and central Thais. The predicted Mi(a+)frequency among southern Thais was significantly lower than among central and northern Thais (p&lt;0.05). Its frequency was similar to Vietnamese, Taiwanese, and Southern Han Chinese populations (p&gt;0.05) but significantly differed from Indonesian, Filipino, and Chinese (Guangzhou) populations (p&lt;0.05). The risk of Mia alloimmunization among southern Thais was significantly lower than among both Thai groups (p&lt;0.05).&#x0D; Conclusion: This constitutes the first study to report Mi(a+) frequencies among southern Thais, supporting the estimation risk of alloimmunization and providing transfusion safety among Thai populations.

Development of DO*A and DO*B Allele Detections to Predict Transfusion-Induced Alloimmunization Risks in Thai Populations.

Two antithetical antigens, Doa and Dob of the Dombrock (DO) blood group system are implicated in acute to delayed hemolytic transfusion reactions among patients with anti-Doa or anti-Dob. Given the unavailability of specific antiserum, a polymerase chain reaction with sequence-specific primer (PCR-SSP) was developed to identify DO*A and DO*B alleles. This study aimed to determine DO*A and DO*B allele frequencies and to predict transfusion-induced alloimmunization risks in three Thai blood donor populations. DNA samples obtained from 1,300, 300, and 400 blood donors from central, northern, and southern Thailand, respectively, were genotyped for the DO*A and DO*B allele detections using developed PCR-SSP. The results were confirmed by DNA sequencing. The validated genotyping results by PCR-SSP were in concordance with DNA sequencing. The DO*B/ DO*B was the most common genotype (77.0, 76.0, and 71.0%), followed by DO*A/DO*B (21.0, 22.7, and 25.2%) and DO*A/DO*A (2.0, 1.3, and 3.8%) among central, northern and southern Thais, respectively. The alleles found among central Thais showed significant differences from those found among southern Thais but not from those of northern Thais. The risk of anti-Doa production was higher than anti-Dob production among Thais. Concerning regional groups, the risk of Doa alloimmunization among southern Thais (0.2059) was higher than those among central (0.1771) and northern Thais (0.1824). This was the first study to distinguish DO*A and DO*B genotypes in Thai populations using in-house PCR-SSP. This would be useful to predict alloimmunization risks that might result from transfusion-induced reactions of undetermined red cell antigens among blood donors and in reagent red cells.

Borderline hemoglobin A2 levels in northern Thai population: HBB genotypes and effects of coinherited alpha-thalassemia

IntroductionIdentification of beta-thalassemia carrier in prenatal screening relies on the elevated Hb A2 level. Borderline Hb A2 levels pose a diagnostic challenge. We determined the HBB genotypes in subjects with borderline Hb A2 in northern Thailand and studied the effects of coinherited alpha0-thalassemia on Hb A2 levels. MethodsBlood samples with Hb A2 3.1–10.0% from 2193 samples submitted for prenatal thalassemia screening were selected. Information on HBB genotypes and coinherited alpha0-thalassemia were collected. All samples with unknown HBB genotypes underwent an automated DNA sequencing. The Hb A2 levels were compared according to the coinherited alpha0-thalassemia. ResultsHBB mutations were found in 298 (98.7%) of 302 samples with Hb A2 4.0–10.0%. In the 106 samples with Hb A2 3.1–3.9%, six had HBB mutations; four Hb Dhonburi [codon 126 (T > G)], one CAP site mutation [CAP + 1 (A > C)] and one beta0-thalassemia [codon 41/42 (-TTCT)] with a coinherited HBD mutation [nt-77 (T > C)]. The Hb A2 levels in beta-thalassemia carriers with and without coinherited alpha0-thalassemia were not significantly different. ConclusionsHBB mutations in northern Thais with borderline Hb A2 levels comprise an unstable variant Hb Dhonburi and CAP + 1 (A > C) mutation. Coinherited HBD mutation lowers Hb A2 and can cause a misidentification of a beta-thalassemia carrier.

Predicted S and s phenotypes from genotyping results among Thai populations to prevent transfusion-induced alloimmunization risks

BackgroundS and s antigens of the MNS system are of clinical importance because alloanti-S and -s have usually caused delayed hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. Various red cell genotyping has been established to predict the phenotypes to solve serological test limitations. Objectives and methodsThis study aimed to determine S and s genotype frequencies and to estimate the alloimmunization risks among central, northern and southern Thai populations. Altogether, 1237 blood samples from Thai blood donors were included. Only 150 samples were tested with anti-S and anti-s by indirect antiglobulin test. All samples were genotyped for GYPB*S and GYPB*s alleles using inhouse PCR with sequence-specific primer. Additionally, the allele frequencies were used to estimate alloimmunization risks and compare with other populations. ResultsThe phenotyping and genotyping results in 150 samples were in 100% concordance. The allele frequencies of GYPB*S in central, northern and southern Thais were 0.061, 0.040 and 0.097, and GYPB*s were 0.939, 0.960 and 0.903, respectively. The frequencies among central Thais were similar to those among northern Thai and Korean populations (P > 0.05) but significantly differed from those of Asian, Caucasian African American and Hispanic populations (P < 0.05). In addition, the risk of S alloimmunization among southern Thais (0.1566) was higher than those among central (0.1038) and northern Thais (0.0736). ConclusionThis was the first study to report S and s predicted phenotypes and estimate alloimmunization risks among Thais, which is beneficial to prevent transfusion-induced alloimmunization among donors and patients.

Antioxidant of green tea and pickle tea product, miang, from northern Thailand

Consumption of tea offers health benefits attributed to phenolic compounds. In Thailand, tea mostly belongs to Camellia sinensis var. assamica which is grown in the northern region. Although, Assam tea cultivation is for tea manufacture, it is also originally grown as part of the forest and is being recognized as agroforestry system. Local northern Thais commonly use mature tea leaves to make a pickle tea product called 'miang' to chew on during working hours (similar to chewing tobacco) and as a common household guest reception snack. While this product still has low economic value, it is gradually gaining more attention from Thai researchers due to its health benefit potential. This study aims to investigate phenolic content in miang in comparison to the benchmark green tea product. A sample of freshly picked tea shoots (the first top 3 leaves) and mature tea leaves (leaves 4-6 from top) and the processed products from tea shoots and mature tea leaves (green tea and miang, respectively) from the same crop were compared in terms of total phenolic content and antioxidant activity measured by FRAP and ORAC assay. The results indicated lower content of phenolic compounds and antioxidant activity measured by both assays in mature tea leaves compared to tea shoots. However, when green tea and miang were extracted under conditions that mimic normal consumption manner, i.e., brewing for green tea and grinding for miang, the results showed that miang had a comparable amount of total phenolic content and antioxidant activity. The results from the same extraction conditions between green tea and miang is also provided in this paper.

FCGR3B gene frequencies among ethnic Thai blood donors from a regional hospital in Eastern Thailand.

The FCGR3B gene encodes three human neutrophil antigens which consist of HNA-1a, HNA-1b, and HNA-1c. These antigens are encoded by three alleles in the FCGR3B locus: FCGR3B*01, FCGR3B*02, and FCGR3B*03 alleles, respectively. The frequencies of FCGR3B alleles have been reported in different ethnic populations. This study compared the FCGR3B gene frequencies among 230 unrelated healthy Eastern Thai blood donors in Rayong hospital with the previously published studies. The polymerase chain reaction-sequence-specific primers method was performed to determine FCGR3B genotypes. The results showed that the allele frequencies of FCGR3B*01, FCGR3B*02, and FCGR3B*03 were 0.722, 0.274, and 0.009, respectively. The FCGR3B*01 and FCGR3B*02 frequencies found in the Eastern Thais were similar to the previous reports investigating in Northern Thais, Chinese Han, Taiwanese, and Japanese populations. Interestingly, our data showed statistically significant difference (P < 0.05) to Central Thais, Korean, Indian, Turkish, Australian, Tunisian, American, German, and Italian populations. In addition, one FCGR3Bnull , which represents a gene deletion, was also found in this study. This information is important not only for the assessment of neutrophil antibody-mediated clinical conditions and for disease association studies but also for anthropological studies.

Risk estimation of HNA-3 incompatibility and alloimmunization in Thai populations.

Severe transfusion-related acute lung injury (TRALI) is often due to antibodies in blood components directed against human neutrophil antigen (HNA)-3a. This study aimed to report the genotype frequencies of the HNA-3 system and to estimate the potential risk of HNA-3 incompatibility and alloimmunization in two Thai populations. Eight hundred DNA samples obtained from 500 unrelated healthy blood donors at the National Blood Centre, Thai Red Cross Society, Bangkok and 300 samples from the Blood Bank, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand were included. HNA-3 genotyping was performed using an in-house polymerase chain reaction with sequence-specific primer (PCR-SSP) technique. The observed frequencies of the HNA-3a/3a, HNA-3a/3b, and HNA-3b/3b genotypes were 0.528, 0.380, and 0.092 in central Thais and 0.600, 0.350, and 0.050 in northern Thais, respectively. The frequencies were used to estimate HNA-3 incompatibility and risk of HNA-3a alloimmunization. The HNA-3 incompatibility in central Thais (33.28%) was higher than northern Thais (28.75%), corresponding to a significantly higher probability of HNA-3a alloimmunization (P<0.05) similar to Japanese and Chinese populations. This study showed the high risk of HNA-3 incompatibility and alloimmunization, especially in central Thai blood donors. A molecular-based identification of the HNA-3 genotype of female donors is suggested to reduce the risk of TRALI following plasma and whole blood allogeneic transfusion.

Frequencies of human neutrophil antigen-4 and human neutrophil antigen-5 among Thai blood donors.

Context:Antibodies against human neutrophil antigens (HNAs) are implicated in immune-mediated neutropenia, transfusion-related acute lung injury and febrile transfusion reactions.Aims:This study aimed to determine HNA gene frequencies of the HNA-4 and HNA-5 systems among Thai populations and compare these frequencies with those previously reported for other populations.Materials and Methods:800 DNA samples obtained from 500 unrelated healthy blood donors from Bangkok and 300 samples from Chiang Mai, Thailand were included. Samples were typed for each HNA allele including HNA-4a, HNA-4b, HNA-5a, and HNA-5b using an in-house polymerase chain reaction with sequence-specific primer technique.Results:The frequencies of HNA-4a and HNA-4b alleles in central Thais were 0.975 and 0.025, respectively and for Northern Thais, their frequencies were 0.965 and 0.035, respectively. For HNA-5a and HNA-5b alleles, their frequencies were 0.771 and 0.229; 0.748, and 0.252 in central and Northern Thais, respectively. The frequencies of HNA-4 and HNA-5 systems in central Thais are closely related to those in Northern Thais (P > 0.05). However, their frequencies were different from other populations (P < 0.001), except HNA-5a and HNA-5b gene frequencies in Thais were similar to Caucasians (P > 0.05).Conclusion:This study could contribute to predict the risk of alloimmunization to HNA-4 and HNA-5 systems, especially in feto-maternal incompatibility in Thais.

Kidd blood group allele frequencies in Thai blood donors.

We present Kidd blood group allele frequencies in Thai blood donors and compare them with other frequencies for other populations previously reported. Eight hundred blood samples obtained from 500 central Thais and 300 northern Thais were genotyped by allele specific-PCR. It was found that JK*01 and JK*02 allele frequencies were 0.503 and 0.497 in central Thais, while the frequencies were 0.498 and 0.502 in northern Thais. The JK*01 and JK*02 allele frequencies in Thais were similar to those in Chinese populations, whereas the frequencies were significantly different from Japanese, French Basques, and African-Americans. This is the first to report of Kidd blood group allele frequencies in Thais, which is beneficial for the prevention of both alloimmunization and adverse transfusion reactions.

Frequency of FCGR3B Alleles in Thai Blood Donors

BackgroundHuman neutrophil antigens (HNAs) are involved in autoimmune and alloimmune neutropenia and transfusion-related acute lung injury. The HNA-1 system is important in immunogenetics, and allele frequencies have been described in different populations. This study investigated the frequency of FCGR3B alleles encoding HNA-1a, HNA-1b, and HNA-1c among Thai blood donors and compared these frequencies with those previously reported for other populations.MethodsEight hundred DNA samples obtained from unrelated healthy blood donors at the National Blood Centre, Thai Red Cross Society, Bangkok, and the Blood Bank, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand, were included. Samples were simultaneously typed for each FCGR3B allele using an in-house polymerase chain reaction with sequence-specific primer (PCR-SSP) technique.ResultsThe frequencies of FCGR3B*1, FCGR3B*2, and FCGR3B*3 alleles in central Thai blood donors were 0.548, 0.452, and 0.004, respectively; only FCGR3B*1 and FCGR3B*2 alleles were found in northern Thai blood donors (0.68 and 0.32, respectively). Compared with other Asian populations, central Thais had higher frequencies of the FCGR3B*2 allele (P<0.001), while the frequencies of the FCGR3B*1 and FCGR3B*2 alleles in northern Thais were similar to those previously reported in Taiwanese and Japanese populations. In contrast, the frequencies of the FCGR3B*1 and FCGR3B*2 alleles in the northern Thai population were statistically different from those observed in central Thai, Korean, German, and Turkish populations.ConclusionsFCGR3B allele frequencies were significantly different between central and northern Thai blood donors. Our in-house PCR-SSP method is a simple, cost-effective, and convenient method for FCGR3B allele detection.

HLA‐B*27 subtypes in Northern and Northeastern Thais, Karens, and Bamars determined by a high‐resolution PCR‐SSP technique

Human leukocyte antigens (HLA), class I, are a group of antigens expressed on most nucleated cell surfaces. They transport endogenous peptides to the cell surface for recognition by T-cell receptors. Their functions are involved in immune responses. Many diseases are associated with HLA alleles, especially HLA-B*27 that is strongly associated with ankylosing spondylitis (AS). HLA-B*27 consists of 42 subtypes. Different subtypes of HLA-B*27 were reported in different ethnic groups of AS patients. In this study, a high-resolution polymerase chain reaction-sequence-specific primer technique has been developed to define all the HLA-B*27 subtypes with a total of 29 primer mixtures. Two of the primer mixes were used to detect the HLA-B*27-specific group, and 27 primer mixes were used to identify 42 subtypes (B*2701-B*2721 and B*2723-B*2743). The HLA-B*27-group-specific primers have been tested in unrelated healthy subjects; 846 Northeastern Thais (NET), 334 Northern Thais (NT), 264 Karens, and 310 Bamars. Sixty-three NET (phenotype frequency, PF = 7.4%), 24 NT (PF = 7.1%), 5 Karens (PF = 1.8%), and 12 Bamars (PF = 3.9%) were positive for HLA-B*27. Only B*2704 was found in Karens, whereas B*2704, B*2705/37/39, B*2706, and B*2707 were found in NET and NT. In Bamars, B*2704, B*2705/37/39, B*2706, and B*2725 were found. The distribution of HLA-B*27 subtypes was compared with other studies in Asian and Caucasian populations. Significant differences of the distribution of HLA-B*27 subtypes were found in most of the populations. This study established a simple technology for HLA-B*27 subtyping and provided basic information for anthropology and further studies in disease associations.

Lymphocyte homeostasis in HIV-infected northern Thais.

Cross-sectional laboratory data were used to model the patterns of total lymphocyte count and lymphocyte subpopulation counts among persons with chronic HIV-1 subtype E (CRF01_AE) infection during the 6.5 years preceding death. The data cover 331 HIV-infected decedents from a heterosexual HIV transmission study of 590 northern Thai couples enrolled in 1992-1998. From blood collected at enrollment, the lymphocyte phenotypes (CD3, CD8, CD4, natural killer, and B cells) were stained using two-color monoclonal antibody combinations and quantified by flow cytometry. Piecewise linear splines modeled the associations between lymphocyte levels and time before death. Mean CD3, CD8, and B cell levels showed no temporal associations from 6.5 to 2 years before death, but each declined significantly during the 2 years before death. CD3 levels declined 31.0% [95% confidence interval (-40.3%, -19.8%)] and CD8 levels declined 24.6% (-35.4%, -13.5%) annually in the 2 years prior to death. In contrast, CD4 and NK cell levels declined little from 6.5 to 4.5 years before death but declined significantly over the 4.5 years prior to death. CD4 levels declined 22.1% (-29.2%, -12.0%) annually from 4.5 to 2 years prior to death and 63.7% (-72.3%, -53.6%) annually over the remaining 2 years. Similar lymphocyte patterns have been reported in U. S. and European populations with HIV-1 subtype B infection.

Identification of DYS385 Allele Variants by Using Shorter Amplicons and Northern Thai Haplotype Data

Primers currently used for amplification of locus DYS385 on the Y chromosome give quite long amplicons that are difficult to resolve on native polyacrylamide gels. We therefore designed new primers that give much shorter products for easy separation. With this system, two allele variants that were characterized by sequencing as 14.1 (GAAA --> GAAAA) and 14.2 (GA insertion), were identified in two unrelated Northern Thai men due to their decreased mobility. Interestingly, initial capillary electrophoresis mistyped the 14.1 variant amplified with the traditional primers as allele 14. Forty different haplotypes were found in 147 Northern Thais with a haplotype diversity of 0.9430. Haplotype 13-18 (frequency 0.136) is the most frequent one: for comparison: haplotype 14-18 (frequency 0.074) was found to be the most common in a population from Bangkok (n = 95) in an earlier study. This striking difference within Thailand's population probably results from genetic differences in the founding populations.

Attitudes toward Democracy among Bangkok and Rural Northern Thais: The Great Divide

Research Article| September 01 1996 Attitudes toward Democracy among Bangkok and Rural Northern Thais: The Great Divide Jim LoGerfo Jim LoGerfo Search for other works by this author on: This Site PubMed Google Scholar Asian Survey (1996) 36 (9): 904–923. https://doi.org/10.2307/2645538 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Jim LoGerfo; Attitudes toward Democracy among Bangkok and Rural Northern Thais: The Great Divide. Asian Survey 1 September 1996; 36 (9): 904–923. doi: https://doi.org/10.2307/2645538 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAsian Survey Search This content is only available via PDF. Copyright 1996 The Regents of the University of California Article PDF first page preview Close Modal You do not currently have access to this content.

Attitudes toward Democracy among Bangkok and Rural Northern Thais: The Great Divide

Attitudes toward Democracy among Bangkok and Rural Northern Thais: The Great Divide

Frequency distribution of D1S80 alleles in the northern Thai population analyzed by amplified fragment length polymorphism technique

A population study on the D1S80 locus in 100 northern Thais was performed using polymerase chain reaction (PCR) and high resolution polyacrylamide gel electrophoresis. Sixteen alleles and 39 genotypes were observed with a heterozygosity of 82%. In contrast to other studies, the allele with 31 repeat units was found to be the most common, followed by alleles 24 and 18. Alleles with more than 41 repeat units were also observed in this study. When applying statistical tests for Hardy-Weinberg equilibrium, no significant deviations were found in this Thai population. The average power of exclusion (in no-parent and one-parent cases) and the discriminating power (DP) was calculated to be 0.52, 0.69 and 0.94, respectively.

HLA antigen, gene, and haplotype frequencies in Thailand.

Antigen, gene, and haplotype frequencies as well as phenotype distribution of the HLA system were studied in a series of 213 individuals in northern Thailand. The series consisted of 160 northern Thais, 23 Thai individuals from various other regions of Thailand, and 25 persons of Chinese origin. Most frequently found were the alleles HLA-A11 and HLA-Bw40 and the haplotype HLA-A2,B-. Phenotype distribution followed a Hardy-Weinberg expectation. Significant differences were found especially between our results for the alleles of locus B and the results of a series from Bangkok reported by Chiewsilp and Chanarat (1976).