HLA‐B*15 subtypes in the population of north‐eastern Thailand

The HLA‐B*15 group is the most polymorphic HLA‐B allele and so has several subtypes. These subtypes have not been defined in the population of north‐eastern Thailand (NET). In a previous study, using polymerase chain reaction–sequence‐specific primers (PCR‐SSP), subtypes were categorized into four groups, namely: group I: HLA‐B*15 (01, 04–07, 12, 14, 19, 20, 24, 25, 26N, 27, 32, 33, 34 and 35); group II: HLA‐B*15 (02, 08, 11, 15, 28 and 30); group III: HLA‐B*1503/4802; group IV: HLA‐B*1521. Groups I and II occurred frequently (allele frequency = 8.0 and 2.5%), and thus we optimized the polymerase chain reaction–single‐stranded conformation polymorphism (PCR‐SSCP) method to identify HLA‐B*15 subtypes of groups I and II. Eighty samples of DNA carrying HLA‐B*15 from 300 healthy unrelated individuals were tested. B*1502 (52.5%) and B*1525 (13.8%) were the most common subtypes found in NET. They also showed strong linkage disequilibrium with HLA‐Cw and heterogeneity of HLA‐A, DR, DQ haplotypes. Although limited conclusions can be drawn from this study because of the small number of DNA references used, the baseline data will be useful in the selection of common HLA‐B*15 alleles when subtyping for unrelated donor transplantations.     

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*27 43). 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.     

HLA-B*15 subtypes in Burmese population by sequence-based typing

Human leukocyte antigen (HLA)-B*15 encompasses an increasing number of subtypes of more than 150. Frequency studies and a strong genetic association between HLA subtypes and susceptibility to drug hypersensitivity have been reported in different ethnic populations. To identify HLA-B*15 subtypes in Burmese using sequence-based typing (SBT) method, we selected 65 HLA-B*15 -positive samples from 170 unrelated healthy Burmese who were genotyped HLA-B * by polymerase chain reaction with the sequence-specific primer method. The frequency of HLA-B*15 in Burmese was found to be 38.2%. By the SBT method, results showed 10 alleles of HLA-B*15 subtypes. Four common alleles, B*1502 (45.2%), B*1532 (16.4%), B*1525 (12.3%), and B*1501 (8.2%), were found in 82.1% of HLA-B*15 -positive Burmese. Whereas the B*1501 was the highest in the Caucasians, Koreans, and Japanese, the highest frequency of HLA-B*15 alleles in Burmese was B*1502 (45.2%) that is similar to the frequency found in northeastern Thais and Vietnamese. This study is the first report of HLA-B*15 subtypes in Burmese. These results will provide the basic data in the further study in transplantations, genetic association with diseases, and drug hypersensitivity.     

辽宁汉族人群HLA-B等位基因多态性的分布

目的调查辽宁汉族人群HLA-B等位基因的遗传多态性。方法用聚合酶链反应．序列特异性引物方法对辽宁8962名健康无关汉族人进行HLA-B等位基因分型，计算HLA-B等位基因频率并与不同人群HLA-B等位基因的多态性进行比较。结果共检出HLA-B等位基因34种，其中B＊15（14．42％）、B＊40（14．33％）和B＊13（11．99％）基因频率分布较高，B＊82、B＊83等位基因未检出；HLA-B座位特异性49种。该人群与南北方汉族人群、日本人、黑人和白人分别进行X^2检验差异有统计学意义，X^2值分别为1584．799、72．145、1393．339、7406．288和5311．947。结论辽宁汉族人群HLA-B基因多态性分布有其自身特点，它的遗传特征不同于既往的南、北方汉族。     

Polymorphism of HLA class I genes in the Brazilian population from the Northeastern State of Pernambuco corroborates anthropological evidence of its origin

The allelic distribution of human leukocyte antigen (HLA) class I genes (HLA-A, HLA-B, and HLA-Cw) of the population from the State of Pernambuco in Northeastern Brazil was studied in a sample of 101 healthy unrelated individuals. Low to medium resolution HLA class I typing was performed using polymerase chain reaction-amplified DNA hybridized to sequence specific primers (PCR-SSPs). Twenty allele groups were detected for HLA-A, 28 for HLA-B, and 14 for HLA-Cw. The most frequent alleles were HLA-A*02(0.2871), HLA-B*15(0.1238), and HLA-Cw*04(0.2277), and the most frequent genotypes were A*02/A*02(0.0990), B*15/B*15(0.0594), and Cw*04/Cw*04 and Cw*07/Cw*07, both with a frequency of 0.0792. The observed heterozygosity for the studied loci was 79.21% for HLA-A, 87.13% for HLA-B, and 77.23% for HLA-Cw. The most frequent haplotype was A*02-Cw*04-B*35(0.0485), which is also present in Western European, Amerindian, and Brazilian Mulatto populations, but absent in African populations. Taken together, these data corroborate the historic anthropological evidences of the origin of the Northeastern Brazilian population from Pernambuco.     

HLA-B*15 diversity in the Korean population

Alleles in the HLA-B*15 group encode molecules belonging to several serologic subgroups, B15 (B62, B63, B75, B76, B77) and B70 (B71, B72), representing many of the most problematic types to assign in routine clinical typing laboratories due to their serologic cross-reactivity resulting from structural similarity. More than 25% of Koreans express HLA-B molecules encoded by the HLA-B*15 alleles. To further characterize HLA-B*15 in this population, B*15-specific polymerase chain reaction (PCR) and sequence-specific oligonucleotide probe (SSOP) hybridization analysis using 39 digoxigenin-labeled probes were applied to DNA samples obtained from 237 B15/B70 serologically positive unrelated individuals. Nine B*15 alleles were identified. B*1501 was the most frequent allele (64.8%) followed by B*1511 (14.1%), B*1507 (8.6%), and B*1518 (5.5%) comprising more than 90% of B*15-positive samples. B62 molecules encoded by 4 of the identified alleles (B*1501, B*1507, B*1525, and B*1527) could not be discriminated by serologic reaction patterns. Among the fifteen B15/B70 apparent homozygotes, eight were heterozygotes carrying two different B*15 alleles. Several B*15 alleles exhibited strong associations with specific Cw, DRB1, and A allelic types (e.g., B*1507-Cw3 (22/22); B*1507-DRB1*04 (21/22), B*1507-A24 (17/22)). The data obtained in this study confirmed B*15 diversity in the study population and will be useful in hematopoietic stem cell donor searches as well as in determining the supplementary DNA typing strategy for B15/B70-positive samples in this population.     

Human leukocyte antigen class I and class II allele frequencies and HIV-1 infection associations in a Chinese cohort

China has one of the most rapidly spreading HIV-1 epidemics. To develop a vaccine targeted to specific human leukocyte antigen (HLA) epitopes in this population, allele distribution analysis is needed. We performed low-resolution class I and II HLA typing of a cohort of 393 subjects from mainland China using a polymerase chain reaction with sequence-specific primers (PCR-SSPs). We found 10 class I alleles present in more than 10% of the population: HLA-A*02, HLA-A*11, HLA-A*24, HLA-B*13, HLA-B*15, HLA-B*40, HLA-Cw*03, HLA-Cw*07, HLA-Cw*01, and HLA-Cw*06. Several class II alleles were found at high frequency (>or=10%): HLA-DRB3, HLA-DRB4, HLA-DRB5, HLA-DRB1*0701, HLA-DRB1*1501, HLA-DRB1*0401, HLA-DRB1*0901, HLA-DRB1*1201, HLA-DQB1*0601, HLA-DQB1*0301, HLA-DQB1*0201, HLA-DQB1*0501, and HLA-DQB*0303. We also estimated 2- and 3-locus haplotype frequencies. Because this cohort contained 280 HIV-1-seropositive and 113 HIV-1-seronegative individuals, we compared allele and haplotype frequencies between the infected and control groups to explore correlations between HLA antigens and susceptibility/resistance to HIV infection. The HLA-B*14 allele was only found in the HIV-1-seropositive group, and many 2-locus haplotypes were significantly overrepresented in this group: HLA-B*14/Cw*08, HLA-B*51/Cw*14, HLA-A*02/B*13, HLA-A*31/Cw*14, HLA-A*02/Cw*06, and the class II haplotype HLA-DRB1*1301/DQB1*0601. Alleles significantly increased in the HIV-1-seronegative controls were HLA-B*44, HLA-Cw*04, and HLA-DRB1*1402. Overrepresented 2-locus haplotypes in the control group were HLA-B*44/Cw*04, HLA-A*31/Cw*03, HLA-A*03/Cw*07, HLA-A*11/B*13, HLA-A*11/B*38, HLA-A*24/B*52, and HLA-A*11/Cw*01. The 3-locus haplotypes HLA-A*24/Cw*03/B*40 and HLA-A*02/B*15/DRB1*1201 were found to be increased significantly in the control group. These data contribute to the database of allele frequencies and associations with HIV infection in the Chinese population.     

New HLA-B alleles identified and sequences extended in potential bone marrow donors: B*5804, B*4418, B*1558, and B*4805

Nucleic acid-based methods for allele identification have revealed more than 470 polymorphic variants at the HLA-B locus. Screening of potential bone marrow donors with sequence specific primer polymerase chain reactions and sequence specific oligonucleotide probe hybridization assays revealed apparent variants within the B*58, *44, *15, and *48 allele groups. DNA sequencing of cloned DNA identified the new alleles B*5804, B*4418, and B*1558 within these groups and observed new sequence information for the previously reported allele B*4805. These findings further extend our knowledge of the substantial genetic variation present at the HLA-B locus within human populations.     

Definition of a new HLA-B7 subtype (B*0704) by isoelectric focusing, family studies and DNA sequence analysis

Abstract: During screening of potential bone marrow donors, a previously undescribed banding position for the serologically defined HLA-B7 antigen was identified in three unrelated families using one dimensional isoelectric focusing and class I specific Western blot analysis. The isoelectric point of the new variant is more acidic than the two HLA-B7 variants that had been defined before. In each family the new B7 variant was found linked to HLA-A2 and -Cw7. Cloning and sequencing of full-length clones of complementary DNA showed that the new allele (B*0704) differs from B*0702, the common allele encoding HLA-B7, by three nucleotide substitutions within the codon for residue 156 of the mature heavy chain. As a result of these differences amino acid 156 is changed from arginine to aspartic acid, a difference consistent with the isoelectric points. The group of three nucleotide substitutions that distinguish B*0704 from B*0702 is present in other HLA-B alleles.     

HLA-B27 polymorphism in Mumbai, Western India

Human leucocyte antigen (HLA)-B27 encompasses an increasing number of subtypes that show diverse racial/ethnic prevalence in the world. One thousand-one-hundred and seventy unrelated individuals from Mumbai, Maharashtra, Western India were typed for HLA-B27 antigen by serological methods. HLA-B27 positivity was confirmed by polymerase chain reaction using sequence specific primers. High-resolution typing using sequence specific primers for HLA-B27 alleles (B*2701 - B*2721) was carried out in 70 HLA-B27-positive individuals. The frequency of B27 ranged between 1.48 and 9.6% among the caste groups studied. HLA-B27 subtyping identified B*2702 (1.43%), B*2704 (14.29%), B*2705 (70%), B*2707 (12.86%) and B*2718 (1.43%), respectively. The findings illustrate substantial genetic variation and heterogeneity within population groups from India. Extensive subtyping in other Indian caste groups will be necessary to resolve the evolutionary implications of HLA-B27 subtypes and their relationship to disease association in the Indian context.     

用等位基因组特异性引物扩增技术确认HLA-B新等位基因B*15:129

目的 对人类白细胞抗原(human leukocyte antigen,HLA)新等位基因HLA-B*15:129的第2～4外显子序列进行分析.方法 采用商用抽提试剂盒抽提标本DNA,应用等位基因组特异性引物PCR方法扩增先证者标本HLA-B基因第2～4外显子,PCR产物经酶切纯化后直接进行HLA-B基因第2～4外显子双向测序分析.结果 先证者标本存在2个HLA-B等位基因,1个等位基因为B*07:02,另1个经Blast验证为新的等位基因,新的等位基因序列已递交GenBank(EF473219),经世界卫生组织HLA命名委员会正式命名为HLA-B*15:129.HLA-B*15:129第2～4外显子序列与最接近的B*15:01:01:01相比,第3外显子存在3个碱基的不同,即第362位G→A、363位G→T、369位C→T改变,导致第97位氨基酸Arg→Asn.结论 发现1例新的HLA-B等位基因,被世界卫生组织HLA基因命名委员会正式命名为HLA-B*15:129.

Abstract：

Objective To analyze the sequence of the exons 2-4 of human leukocyte antigen (HLA) novel allele HLA-B*15:129.Methods DNA of the proband was extracted from whole blood by commercial DNA extraction kit. The amplification for HLA-B exons 2-4 was performed separately by polymerase chain reaction (PCR) with allele group specific primers. The PCR products were digested with enzymes and then directly sequenced for exons 2-4 of HLA-B locus in both directions.Results Sequencing results showed the HLA-B alleles of the proband included B*07:02 and a novel allele. The sequence of the novel allele has been submitted to GenBank (accession no. EF473219) and the allele has been officially named B*15:129 by the WHO Nomenclature Committee. Comparing with the HLA-B*15:01:01:01, the sequence of exons 2-4 of HLA-B*15:129 showed three nucleotide difference in exon 3 at positions 362 and 363 from GG to AT and positions 369 from C to T, which resulted in an amino acid change from Arg to Asn at codon 97.Conclusion A novel HLA-B allele was identified and has been officially named B15:129 by the WHO Nomenclature Committee.     

Complete HLA-B44 subtyping in Spaniards. Additional evidence for heterogeneity in Caucasian populations

HLA-B44 is one of the most common HLA class I alleles in Caucasians. Exon 3 oligotyping and sequence analysis have define five B44 subtypes: B^*4402, B^*4403, B^*4404, B^*4405 and B^*4406, with variations in exons 2 and 3. We have developed a conventional DNA typing system by using a single B12-group specific amplification including exon2-intron2-exon3 in combination with 6 oligoprobes to define all B44 subtypes. 140 HLA-B44 positive unrelated Spanish Caucasians were typed. Family studies established 30 B44-bearing haplotypes. The distribution of B44 subtypes in our population was: B^*4402 32.5%, B^*4403 66.5%, B^*4404 0.5%, B^*4405 0.5%, B^*4406 not found. B^*4402 and B^*4403 represented the 99% of the B44 alleles, as described in Caucasians. However, these two major subtypes showed an inverted frequency when compared with other Caucasian populations, B^*4403 twice as frequently as B^*4402 in Spaniards. HLA-B44-associated chromosomes showed 20 different haplotypes (including HLA-A,-C,-DR,-DQ), although demonstrating clear separated haplotype composition between B^*4402 and B^*4403: B^*4402 associated to class I alleles A2 ( ) and Cw5 ( ), and B^*4403 associated to the class II allele DRB1^*0701 ( ). These findings, in addition to the validation of a complete B44 oligotyping system, revealed further evidence of antigen frequency differences among populations of the same ethnic origin.     

Polymorphism of HLA class I genes in Meizhou Han population of Guangdong, China

Human leukocyte antigen (HLA) is an invaluable marker for anthropological studies because of its extreme polymorphism. Most of the studies carried out in Chinese populations are about HLA class II genes, but few about class I genes. In the present study, we investigated HLA class I polymorphism using polymerase chain reaction-sequencing-based typing (PCR-SBT) method in 104 unrelated Han individuals in Meizhou of Guangdong, southern China. Twenty-three HLA-A, 43 HLA-B and 27 HLA-C alleles were identified and allele frequencies and two-locus (C/B) and three-locus (A/C/B) haplotypes were statistically analysed. The most frequent HLA-A allele is A*110101 with a frequency of 30.3%, followed by A*24020101 (22.2%) and A*2420 (11.6%). Among the 43 detected HLA-B alleles, B*5801 (17.0%), B*400101 (15.5%) and B*4601 (10.0%) were frequently observed. Among the 27 detected C alleles, the most predominant one is Cw*07020101 (25.8%), followed by Cw*0717 (14.7%). The most frequent HLA-C/B two-locus haplotype is Cw*07020101/B*400101 (10.1%). The most common HLA-A/C/B three-locus haplotype in Meizhou Han is A*110101/Cw*07020101/B*400101 (3.4%). Phylogenetic tree based on HLA class I allele frequencies genetically suggested that Meizhou Han has an affinity to southern Asian populations. The result may also reflect an admixture of Han and ethnic minorities of southern China.     

HLA-B*15 subtypes distribution in Han population in Beijing,China, as compared with those of other populations

To identify HLA-B*15 subtypes distribution in Han population in Beijing, People’s Republic of China, 826 unrelated healthy individuals were typed using the polymerase chain reaction-sequence-based typing method. Within the 246 HLA-B*15 positive individuals, 29 HLA-B*15 alleles were identified, the most predominant of which is B*1501 (40.07%), followed by B*1502 (12.87%), B*1511 (12.87%), B*1518 (9.19%) and B*1532 (3.31%). The distribution of HLA-B*15 subtype frequencies was compared between the Beijing Han, eight other Chinese ethnic minorities and six Chinese populations covering the mainland of China, Taiwan, Hong Kong and Singapore. A neighbor-joining phylogenetic tree was constructed and revealed that the Beijing Han population clustered into the northern populations group and had a closer relationship with northern Han and Hui than with southern Han or other ethnic minorities. These results thus provide useful information that can be used in anthropology, selection for bone marrow transplantation as well as in disease-association study, such as in carbamazepine (CBZ)-induced Stevens–Johnson syndrome and toxic epidermal necrolysis.     

HLA-B*07 allele frequencies and haplotypic associations in Koreans

We have investigated the frequencies of HLA-B*07 alleles and their haplotypic associations with HLA-A, -C and -DRB1 loci in 489 healthy unrelated Koreans, including 214 parents from 107 families. All of the 45 samples (9.2%) typed as B7 by serology were analyzed for B*07 alleles using polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) method. Two different B*07 alleles were detected: B*0702 (allele frequency 0.041) and B*0705 (0.005). Two characteristic haplotypes showing strong linkage disequilibrium in Koreans were A*2402-Cw*07-B*0702-DRB1*0101 (haplotype frequency 0.028) and A*2901-B*0705-DRB1*0803 (0.005). The characteristic haplotype A*2901-B*0705-DRB1*0803, found in 100% (5/5) of B*0705-positive individuals, has not been previously described in other ethnic groups. HLA-B7 alleles comprise distinctive extended haplotypes in the Korean population. The probability of HLA-B7 allele mismatches among ABDR-matched unrelated donor-recipient pairs is expected to be low in Koreans.     

HLA-B40组等位基因多态性和血清学分型不明确标本分析

目的：利用DNA分型技术调查上海汉族人群HLA－B40组等位基因多态性并比较配型标本中HLA－B40抗原血清学和DNA分型的结果：方法：采用反向PCR－SSOP技术进行DNA分型，可检出HLA－B＊4001－4011等11个等位基因，结果：所有标本DNA分型均获成功，无假阳性和假阴性结果出现，质控DNA分型结果与UCLA结果相符，上海地区汉族人群共检出B＊4001－4003，4005－4007，4011等等位基因，未检出B＊4004，4008－4010等等位基因，296名无关个体中HLA－B40＊组等位基因频率为0．1402，血清学方法检测HLA－B40组抗原错误率为12．82％（10／78），结论：该技术用于HLA－B40分型分辨率高，分型结果较血清学方法更加精确，可确保HLA分型的准确。     

HLA-B27 polymorphism in patients with juvenile and adult-onset ankylosing spondylitis in Southern China

Abstract
Distribution of B27 subtypes in juvenile and adult-onset ankylosing spondylitis (JAS and AAS) in Southern China was studied. A total of 505 patients belonged to Han population were included (145 JAS and 360 AAS patients), and 1368 healthy individuals were included as controls. Human leukocyte antigen (HLA)-B27 typing was performed by Luminex liquid array combining polymerase chain reaction-sequence specific oligonucleotide probe (PCR-SSOP) and/or serological method. HLA-B27 subtyping was performed by polymerase chain reaction-sequence specific primer (PCR-SSP). The sequence-based typing was performed for the B*2715 samples to verify the PCR-SSP results. HLA-B27 was presented in 453 of 505 patients (89.7%), compared with 74 of 1368 controls (5.41%). B*2704 subtype in AS group was significantly higher than controls and B*2705 subtype significantly lower. B*2715 and B*2702 were found in 1.32% and 0.66% of the B27-positive patients but none in controls, and there was no significant difference between either of them and controls. B27-positive patients were 134 (92.4%) in JAS group and 319 (88.6%) in AAS group. There was no significant difference for B27 subtypes distribution between JAS (B*2704, 05, 15) and AAS (B*2704, 05, 15, 02) groups. The frequency of B*2715 in two groups was 3 (2.24%) and 3 (0.94%), respectively. The onset age of three JAS patients carrying B*2715 was 5, 9 and 13 years old, respectively. Our results suggested that B*2704 was the predominant subtype in AS patients in Southern China. B*2715 was observed in AS group only and slightly more in JAS than in AAS, and the patients carrying this allele tended to have early onset, B*2715 may be disease-association subtype.     

Diversity of human leukocyte antigen-B27 alleles in Han population of Hunan province, southern China

This study was to investigate the frequency of HLA-B27 and its subtypes in the Han population of Hunan province, southern China. One hundred and sixty-nine healthy unrelated donors were tested for HLA-B27 by polymerase chain reaction-sequence-specific primer (PCR-SSP). One hundred and twenty-eight B27-positive spondyloarthropathy patients and 18 B27-positive healthy controls were subtyped using the high-resolution PCR-SSP. The phenotype frequency of human leukocyte antigen (HLA)-B27 was found to be 2.36% in healthy population. Five B27 alleles were identified: B*2704, B*2705, B*2706, B*2707, and B*2724. No significant difference was found in the distribution of HLA-B27 subtypes between the patients and controls studied. Notably, B*2724 was observed in a juvenile patient with ankylosing spondylitis. This subtype has not been previously reported in Chinese ankylosing spondylitis (AS) patients and other ethnic groups.     

HLA-B27 subtypes determination in patients with ankylosing spondylitis from Zulia,Venezuela

To perform an investigation regarding the distribution of the human leukocyte antigen (HLA)-B27 subtypes in the Zulian population with ankylosing spondylitis (AS), 48 unrelated Mestizos, HLA-B27 positive by serology, were studied using the polymerase chain reaction-specific sequence oligonucleotides probe (PCR-SSOP) and specific sequence primers (SSP) to analyze the polymorphism in exons 2 and 3 of the HLA-B27 gene. Only two of eight HLA-B27 subtypes studied (B*2701-B*2708) were found. The distribution of these alleles in the population of patients was: B*2705, 68.8%, and B*2702, 31.2%. B*2705 subtype showed significant association with patients being male. In the healthy controls, the most common subtype was B*2708. These results were compared with frequencies reported in other Mestizo and Spanish populations and showed significant differences, such as a high frequency of B*2702. Such results show that HLA*B2705 and HLA*B2702 are the subtypes most frequently associated with AS in our Mestizo population and suggest a possible protector role for HLA*B2708, which was found only in the healthy population.     

西藏珞巴族HLA-A,-B基因多态性研究

目的调查西藏地区珞巴族群体HLA—A，—B基因的多态性。方法用聚合酶链反应-序列特异性寡核苷酸探针反向斑点杂交技术，对西藏林芝地区3代内无血缘关系的92个珞巴族健康个体进行了HLA—A，—B位点的基因分型。结果在HLA—A位点共检出10种等位基因，在HLA—B位点检出19种等位基因；在HLA—A位点高频等位基因是HLA—A*11、-A*02、-A*24，它们的频率分别为36．40％、25．50％、23．90％，这3种等位基因共占珞巴族可检出等位基因的85．80％。在HLA—B位点高频基因为HLA—B*40(频率为27．20％)、-B*15(11．40％)和-B*38(10．90％)，它们占等位基因的49．5％。结论珞巴族与其他各华人群体间都存在较大的差异，显示其HLA等位基因频率分布的民族独特性；但其HLA—A、—B等位基因多态性与藏族的很接近，这与民族学、历史学和社会学研究结果相一致。