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Getz J, Goldenstein M, Bonfim C, Funke VM, Colturato V, Hamerschlak N, Torres M, Sayer D, Boldt A, Pasquini R, Pereira NF. Investigation of MHC gamma block C4A and C4B polymorphisms in unrelated hematopoietic stem cell transplantation. Hematol Transfus Cell Ther 2019; 42:221-229. [PMID: 31801701 PMCID: PMC7417459 DOI: 10.1016/j.htct.2019.06.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 06/21/2019] [Accepted: 06/29/2019] [Indexed: 12/21/2022] Open
Abstract
Background Immunological life-threatening complications frequently occur in post-hematopoietic stem cell transplantation (HSCT), despite matching recipient and donor (R/D) pairs for classical human leukocyte antigens (HLA). Studies have shown that R/D non-HLA disparities within the major histocompatibility complex (MHC) are associated with adverse effects post-HSCT. Methods We investigated the impact of mismatches of single-nucleotide polymorphisms (SNPs) in C4A/C4B genes, for showing the highest diversity in the MHC gamma block, on 238 patients who underwent HLA 10/10 unrelated donor (URD) HSCT. The endpoints were acute graft-versus-host disease (aGVHD), chronic graft-versus-host disease (cGVHD) and mortality. One hundred and twenty-nine R/D pairs had 23 C4-SNPs typed by PCR-SSP (Gamma-Type™v.1.0), and 109 R/D pairs had these 23 SNPs identified by next-generation sequencing (NGS) using the Illumina platform. Results The percentage of patients who received HSC from HLA 10/10 donors with 1–7 mismatches was 42.9%. The R/D pairs were considered C4 mismatched when bearing at least one disparity. These mismatches were not found to be risk factors for aGVHD, cGVHD or mortality after unrelated HSCT when SNPs were analyzed together (matched or mm ≥ 1), independently or according to the percentage of incompatibilities (full match for 23 SNPs; 1–3 mm and >3 mm). An exception was the association between 1–3 mismatches at the composite of SNPs C13193/T14952/T19588 with the development of aGVHD (P = 0.012) and with grades III-IV of this disease (P = 0.004). Conclusion Our data are not consistent with the hypothesis that disparities in C4A/C4B SNPs increase the risks of post-HSCT adverse effects for the endpoints investigated in this study.
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Affiliation(s)
- Joselito Getz
- Hospital de Clínicas - Universidade Federal do Paraná (HC-UFPR), Curitiba, PR, Brazil.
| | - Monica Goldenstein
- Hospital de Clínicas - Universidade Federal do Paraná (HC-UFPR), Curitiba, PR, Brazil
| | - Carmem Bonfim
- Hospital de Clínicas - Universidade Federal do Paraná (HC-UFPR), Curitiba, PR, Brazil
| | - Vaneuza Moreira Funke
- Hospital de Clínicas - Universidade Federal do Paraná (HC-UFPR), Curitiba, PR, Brazil
| | | | | | - Margareth Torres
- Hospital Amaral Carvalho, Jaú, SP, Brazil; Hospital Israelita Albert Einstein, São Paulo, SP, Brazil
| | | | - Angelica Boldt
- Hospital de Clínicas - Universidade Federal do Paraná (HC-UFPR), Curitiba, PR, Brazil; Genetics Department - Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Ricardo Pasquini
- Hospital de Clínicas - Universidade Federal do Paraná (HC-UFPR), Curitiba, PR, Brazil; Hospital Nossa Senhora das Graças, Curitiba, PR, Brazil
| | - Noemi Farah Pereira
- Hospital de Clínicas - Universidade Federal do Paraná (HC-UFPR), Curitiba, PR, Brazil
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Murphy NM, Burton M, Powell DR, Rossello FJ, Cooper D, Chopra A, Hsieh MJ, Sayer DC, Gordon L, Pertile MD, Tait BD, Irving HR, Pouton CW. Haplotyping the human leukocyte antigen system from single chromosomes. Sci Rep 2016; 6:30381. [PMID: 27461731 PMCID: PMC4961964 DOI: 10.1038/srep30381] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 06/29/2016] [Indexed: 11/18/2022] Open
Abstract
We describe a method for determining the parental HLA haplotypes of a single individual without recourse to conventional segregation genetics. Blood samples were cultured to identify and sort chromosome 6 by bivariate flow cytometry. Single chromosome 6 amplification products were confirmed with a single nucleotide polymorphism (SNP) array and verified by deep sequencing to enable assignment of both alleles at the HLA loci, defining the two haplotypes. This study exemplifies a rapid and efficient method of haplotyping that can be applied to any chromosome pair, or indeed all chromosome pairs, using a single sorting operation. The method represents a cost-effective approach to complete phasing of SNPs, which will facilitate a deeper understanding of the links between SNPs, gene regulation and protein function.
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Affiliation(s)
- Nicholas M Murphy
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Preimplantation Genetic Diagnosis, Melbourne IVF, Melbourne, VIC, Australia
| | - Matthew Burton
- Flow Cytometry &Imaging, Murdoch Children's Research Institute, Parkville, VIC, Australia
| | - David R Powell
- Bioinformatics Platform, Monash University, Clayton, VIC, Australia
| | - Fernando J Rossello
- Department of Anatomy and Developmental Biology, Monash University, Clayton, VIC, Australia
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, Australia
| | - Don Cooper
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
| | - Abha Chopra
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
| | - Ming Je Hsieh
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | | | - Lavinia Gordon
- Australian Genome Research Facility, The Walter and Eliza Hall Institute of Medical Research, Royal Parade, Parkville, VIC, Australia
| | - Mark D Pertile
- Victorian Clinical Genetics Services, Parkville, VIC, Australia
- Department of Paediatrics, University of Melbourne, Parkville, VIC, Australia
| | - Brian D Tait
- Transplant Services, Australian Red Cross Blood Service, Parkville, VIC, Australia
| | - Helen R Irving
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Colin W Pouton
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
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Genomic evolution and polymorphism: Segmental duplications and haplotypes at 108 regions on 21 chromosomes. Genomics 2013; 102:15-26. [DOI: 10.1016/j.ygeno.2013.02.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 02/13/2013] [Accepted: 02/27/2013] [Indexed: 11/21/2022]
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Polymorphic SVA retrotransposons at four loci and their association with classical HLA class I alleles in Japanese, Caucasians and African Americans. Immunogenetics 2010; 62:211-30. [PMID: 20174920 DOI: 10.1007/s00251-010-0427-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Accepted: 02/01/2010] [Indexed: 01/07/2023]
Abstract
Polymorphic insertion frequencies of the retrotransposons known as the "SVA" elements were investigated at four loci in the MHC class I genomic region to determine their allele and haplotype frequencies and associations with the HLA-A, -B or -C genes for 100 Japanese, 100 African Americans, 174 Australian Caucasians and 66 reference cell lines obtained from different ethnic groups. The SVA insertions representing different subfamily members varied in frequency between none for SVA-HF in Japanese and 65% for SVA-HB in Caucasians or African Americans with significant differences in frequencies between the three populations at least at three loci. The SVA loci were in Hardy-Weinberg equilibrium except for the SVA-HA locus which deviated significantly in African Americans and Caucasians possibly because of a genomic deletion of this locus in individuals with the HLA-A*24 allele. Strong linkage disequilibria and high percentage associations between the human leucocyte antigen (HLA) class I gene alleles and some of the SVA insertions were detected in all three populations in spite of significant frequency differences for the SVA and HLA class I alleles between the three populations. The highest percentage associations (>86%) were between SVA-HB and HLA-B*08, -B*27, -B*37 to -B*41, -B*52 and -B*53; SVA-HC and HLA-B*07; SVA-HA and HLA-A*03, -A*11 and -A*30; and SVA-HF and HLA-A*03 and HLA-B*47. From pairwise associations in the three populations and the homozygous cell line results, it was possible to deduce the SVA and HLA class I allelic combinations (haplotypes), population differences and the identity by descent of several common HLA-A allelic lineages.
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Fliegner RA, Holloway SA, Lester S, McLure CA, Dawkins RL. Evaluation of the class II region of the major histocompatibility complex of the greyhound with the genomic matching technique and sequence-based typing. ACTA ACUST UNITED AC 2008; 72:131-6. [DOI: 10.1111/j.1399-0039.2008.01084.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Lester S, McLure C, Williamson J, Bardy P, Rischmueller M, Dawkins RL. Epistasis between the MHC and the RCA alpha block in primary Sjögren syndrome. Ann Rheum Dis 2008; 67:849-54. [PMID: 17878210 PMCID: PMC2565577 DOI: 10.1136/ard.2007.075044] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2007] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The RCA alpha block (Regulators of Complement Activation, 1q32) contains critical complement regulatory genes such as CR1 and MCP. This study examined RCA alpha block haplotype associations with both disease susceptibility and diversification of the anti-Ro/La autoantibody response in primary Sjögren syndrome (pSS). METHODS 115 patients with pSS and 98 controls were included in the study. 93 of 109 (85%) of the patients with pSS were seropositive for Ro/La autoantibodies. The Genomic Matching Technique (GMT) was used to define RCA alpha block ancestral haplotypes (AH). RESULTS RCA alpha block haplotypes, AH1 and AH3, were both associated with autoantibody-positive pSS (p = 0.0003). Autoantibody associations with both HLA DR3 and DR15 have been previously defined. There was an epistatic interaction (p = 0.023) between RCA alpha AH1 and HLA DR3, and this genotypic combination was present in 48% of autoantibody-positive patients with pSS compared with 8% of controls. This epistasis is most simply attributable to an interaction between C4 and its receptor, CR1, encoded within the RCA alpha block. Both DR3 and a relative C4 deficiency are carried on the major histocompatibility complex 8.1 ancestral haplotype. Only four of 92 (4%) autoantibody-positive patients with pSS did not carry any risk RCA alpha or HLA haplotype, compared with 36 of 96 (38%) controls, and there were differences in haplotype frequencies within autoantibody subsets of pSS. CONCLUSIONS Normal population variation in the RCA alpha block, in addition to the major histocompatibility complex, contributes genetic susceptibility to systemic autoimmune disease and the autoantibody response. This finding provides evidence for the role of regulation of complement activation in disease pathogenesis.
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Affiliation(s)
- S Lester
- C Y O'Connor ERADE Village, Canning Vale, Western Australia, Australia
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7
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Novel sequence elements define ancestral haplotypes of the region encompassing complement factor H. Hum Immunol 2008; 69:207-19. [DOI: 10.1016/j.humimm.2008.01.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Revised: 12/21/2007] [Accepted: 01/04/2008] [Indexed: 11/23/2022]
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Dunn DS, Choy MK, Phipps ME, Kulski JK. The distribution of major histocompatibility complex class I polymorphic Alu insertions and their associations with HLA alleles in a Chinese population from Malaysia. ACTA ACUST UNITED AC 2007; 70:136-43. [PMID: 17610418 DOI: 10.1111/j.1399-0039.2007.00868.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The frequency and association of polymorphic Alu insertions (POALINs) with human leucocyte antigen (HLA) class I genes within the class I genomic region of the major histocompatibility complex (MHC) have been reported previously for three populations: the Australian Caucasian, Japanese and north-eastern Thai populations. Here, we report on the individual insertion frequency of the five POALINs within the MHC class I region, their HLA-A and HLA-B associations, the POALIN haplotype frequencies and the HLA-A/POALIN four-loci haplotype frequencies in the Malaysian Chinese population. The phylogenetic relationship of the four populations based on the five POALIN allele frequencies was also examined. In the Malaysian Chinese population, the POALIN AluyHG was present at the highest frequency (0.560), followed by AluyHJ (0.300), AluyMICB (0.170), AluyTF (0.040) and AluyHF (0.030). The most frequent five-loci POALIN haplotype of the 16 inferred haplotypes was the AluyHG single insertion haplotype at a frequency of 0.489. Strong associations were present between AluyHJ and HLA-A24, HLA-A33 and HLA-A11 and between AluyHG and HLA-A2, HLA-A24 and HLA-A11, and these were reflected by the inferred haplotype frequencies constructed from the combination of the HLA-A locus and the AluyHG, AluyHJ and AluyHF loci. The strongest association of AluyMICB was with the HLA-B54 allele (five of five), whereas the associations with the other 17 HLA-B alleles were weak, moderate or undetermined. Phylogenetic analysis of the five POALIN allele frequencies places the Malaysian Chinese closest to the Japanese and north-eastern Thai populations in the same cluster and separate to the Australian Caucasian population. The MHC POALINs are confirmed in this study to be informative genetic markers in lineage (haplotype) analysis, population genetics and evolutionary relationships, especially in studying the MHC genomic region.
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Affiliation(s)
- D S Dunn
- Centre for Comparative Genomics, School for Information Technology, Murdoch University, Murdoch, Western Australia, Australia
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Kitcharoen K, Witt CS, Romphruk AV, Christiansen FT, Leelayuwat C. MICA, MICB, and MHC Beta Block Matching in Bone Marrow Transplantation: Relevance to Transplantation Outcome. Hum Immunol 2006; 67:238-46. [PMID: 16698448 DOI: 10.1016/j.humimm.2006.02.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2005] [Indexed: 11/19/2022]
Abstract
Genetic testing of the MHC is required for selection of donors for bone marrow transplantation. The outcome of related bone marrow transplantation is usually superior to that of unrelated bone marrow transplantation. This may be the result of inaccurate or incomplete genetic testing employed for selection of donor for transplantation. Based on MHC haplotype matching, MHC block matching has been developed for selection of potential unrelated donor. Block matching has been shown previously to improve outcome when added to the conventional method of human leukocyte antigen (HLA) typing for selection of donors. In this study, we have retrospectively analyzed 44 donor recipient pairs from the Australian Bone Marrow Donor Registry Repository with respect to matching of HLA-B and HLA-Cw by sequence-based typing and MICA and MICB by polymerase chain reaction-sequence specific primer and MHC beta block matching and correlated these results with survival. Beta block matching was correlated with MIC matching (p < 0.005) and with HLA-B and HLA-Cw matching. Patients who were HLA-B and -Cw matched had significantly improved survival when they were additionally matched for MHC beta block (p(c) = 0.04) or MIC (p(c) = 0.05).
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Affiliation(s)
- K Kitcharoen
- Medical Technology Program, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand
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McLure CA, Williamson JF, Smyth LA, Agrawal S, Lester S, Millman JA, Keating PJ, Stewart BJ, Dawkins RL. Extensive genomic and functional polymorphism of the complement control proteins. Immunogenetics 2005; 57:805-15. [PMID: 16283405 DOI: 10.1007/s00251-005-0049-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2005] [Accepted: 08/11/2005] [Indexed: 11/25/2022]
Abstract
Using combinations of genomic markers, we describe more than 20 distinct ancestral haplotypes (AH) of complement control proteins (CCPs), located within the regulators of complement activation (RCA) alpha block at 1q32. This extensive polymorphism, including functional sites, is important because CCPs are involved in the regulation of complement activation whilst also serving as self and viral receptors. To identify haplotypes, we used the genomic matching technique (GMT) based on the pragmatic observation that extreme nucleotide polymorphism is packaged with duplicated sequences as polymorphic frozen blocks (PFB). At each PFB, there are many alternative sequences (haplotypes) which are inherited faithfully from very remote ancestors. We have compared frequencies of RCA haplotypes and report differences in recurrent spontaneous abortion (RSA) and psoriasis vulgaris (PV).
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Affiliation(s)
- Craig A McLure
- CY O'Connor ERADE Village, Canning Vale, Western Australia
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Laird R, Dawkins RL, Gaudieri S. Use of the genomic matching technique to complement multiplex STR profiling reduces DNA profiling costs in high volume crimes and intelligence led screens. Forensic Sci Int 2005; 151:249-57. [PMID: 15939159 DOI: 10.1016/j.forsciint.2005.02.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2005] [Revised: 02/25/2005] [Accepted: 02/26/2005] [Indexed: 10/25/2022]
Abstract
The genomic matching technique (GMT) targets duplicated polymorphic sequences within genomic blocks in the human major histocompatibility complex (MHC), differentiating between individuals at the DNA level using a single primer pair per block. The GMT is currently used to supplement human leukocyte antigen (HLA) typing to match donor and recipient pairs for bone marrow transplantation and has the potential to be employed as a powerful exclusion tool in forensic biology. The GMT is highly reproducible, produces DNA profiles from less than 1 ng of DNA and was successfully employed to profile a range of forensic samples including buccal swabs, handled objects and fingerprints. Furthermore, GMT profiles from a single genomic block in the MHC are likely to be more discriminatory than known highly polymorphic short tandem repeat (STR) loci such as ACTBP2. As such, the GMT can reduce the cost of investigations that require profiling of multiple suspects or samples from one or more crime scenes and could be extended to profile genomic blocks in other polymorphic genetic systems in the human genome.
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Affiliation(s)
- R Laird
- Centre for Forensic Science, School of Anatomy and Human Biology, University of Western Australia, Crawley Ave., Nedlands, WA 6009, Australia
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Marroni F, Curcio M, Fornaciari S, Lapi S, Mariotti ML, Scatena F, Presciuttini S. Microgeographic variation of HLA-A, -B, and -DR haplotype frequencies in Tuscany, Italy: implications for recruitment of bone marrow donors. ACTA ACUST UNITED AC 2005; 64:478-85. [PMID: 15361126 DOI: 10.1111/j.1399-0039.2004.00292.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
HLA-A/B haplotype frequencies were estimated in a sample of 2355 bone marrow donors born in a subregion of Tuscany (Italy), and the HLA-A, -B, -DR haplotype frequencies were estimated in a subset of 809 individuals. This area was divided in 10 subsamples (two-locus haplotypes), or six subsamples (three-locus haplotypes), all with sample size >50, based on administrative boundaries. A considerable level of heterogeneity of haplotype frequency was present among subsamples; this heterogeneity was associated to a large variation (up to 4-fold) of the number of new donors that must be typed in order to reach 50% chance of finding an HLA-A, -B phenotype of intermediate frequency. Knowledge of the genetic structure of the population at a microgeographic level may be useful in directing the search of specific bone marrow donors.
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Affiliation(s)
- F Marroni
- Department of Oncology, Transplants and New Technologies in Medicine, Section of Pathology, University of Pisa, Pisa, Italy
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Gaudieri S, Longman-Jacobsen N, Tay GK, Dawkins RL. Sequence analysis of the MHC class I region reveals the basis of the genomic matching technique. Hum Immunol 2001; 62:279-85. [PMID: 11250045 DOI: 10.1016/s0198-8859(01)00210-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The genomic matching technique (GMT) improves survival following bone marrow transplantation (BMT) between unrelated donor and recipient pairs correlating with a decrease in incidence and severity of graft-versus-host disease (GvHD). The principles of this technique are based on the duplication and polymorphic characteristics of the major histocompatibility complex (MHC). Specifically, the beta block GMT matches for a 300 kb region that contains the human leukocyte antigen (HLA-B and -C) genes as well as other non-HLA genes such as the natural killer cell receptor ligand PERB11 (MIC). The block contains two large segmental duplications. One results in two PERB11 genes (11.1 and 11.2), the other in two class I genes (HLA-B and -C). With the complete sequencing of the class I region of the MHC in different haplotypes, we can now show that the beta block GMT profiles reflect amplification of the duplicated PERB11 segments and not the duplicated segments containing HLA-B and -C, and yet provide a signature that characterizes the entire block rather than individual loci.
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Affiliation(s)
- S Gaudieri
- Centre for Molecular Immunology and Instrumentation, University of Western Australia, Western, Nedlands, Australia
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Tang J, Naik E, Costello C, Karita E, Rivers C, Allen S, Kaslow RA. Characteristics of HLA class I and class II polymorphisms in Rwandan women. EXPERIMENTAL AND CLINICAL IMMUNOGENETICS 2001; 17:185-98. [PMID: 11096257 DOI: 10.1159/000019138] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To define HLA class I and class II polymorphisms in Rwandans. METHODS PCR-based HLA genotyping techniques were used to resolve variants of HLA-A, B, and C to their 2- or 4-digit allelic specificities, and those of DRB1 and DQB1 to their 4- or 5-digit alleles. RESULTS Frequencies of 14 A, 8 C, and 14 B specificities and of 13 DRB1 and 8 DQB1 alleles were >/=0.02 in a group of 280 Rwandan women. These major HLA factors produced 6 haplotypes extending across the class I and class II regions: A*01-Cw*04-B* 4501-DRB1*1503-DQB1*0602 (A1-Cw4-B12- DR15 - DQ6), A * 01 - Cw * 04 - B * 4901 -DRB1 * 1302-DQB1*0604 (A1-Cw4-B21-DR13-DQ6), A*30 - Cw*04 - B*15 - DRB1*1101 - DQB1*0301 (A19-Cw4-B15-DR11-DQ7), A*68-Cw*07-B* 4901-DRB1*1302-DQB1*0604(A28-Cw7-B21- DR13 - DQ6), A*30 - Cw*07 - B*5703 - DRB1* 1303-DQB1*0301(A19 - Cw7 - B17 - DR13 - DQ7), and A*74-Cw*07-B*4901-DRB1*1302-DQB1* 0604 (A19-Cw7-B21-DR13-DQ6), respectively. Collectively, these extended haplotypes accounted for about 19% of the total. Other apparent class I-class II haplotypes (e.g., Cw*17-B*42-DRB1*0302-DQB1*0402, Cw*06- B*58-DRB1*1102-DQB1*0301, and Cw*03- B*15-DRB1*03011-DQB1*0201) did not extend to the telomeric HLA-A locus, and other 3-locus class I haplotypes (e.g., A*68-Cw*04-B*15, A*74-Cw*04-B*15, and A*23-Cw*07-B*4901) completely or partially failed to link with any specific class II alleles. DISCUSSION Frequent recombinations appeared to occur between the three evolutionarily conserved HLA blocks carrying the class I and class II loci. The HLA class I profile seen in Rwandans was not directly comparable with those known in the literature, although the class II profile appeared to resemble those in several African populations. These data provide additional evidence for the extensive genetic diversity in Africans.
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Affiliation(s)
- J Tang
- Division of Geographic Medicine, Department of Medicine, University of Alabama at Birmingham, 39294-0022, USA
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