C4B gene polymorphisms among African and African-American HLA-Bw42-DRw18 haplotypes

Fraser, Patricia A.; Awdeh, Zuheir L.; Ronco, P; Simon, Susan; Moore, B. P. L.; Fici, D; Marcus-Bagley, Deborah; Yunis, Edmond J.; Alper, Chester A.

doi:10.1007/bf00212312

Cited by 9 publications

(2 citation statements)

References 25 publications

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“…Recently, different extended haplotypes have been described for different races, African-Americans for example (5). In general, extended haplotypes are highly characteristic of an ethnic or racial group and can have lower frequencies or not occur at all in other groups (6). Initial attempts to define linkage disequilibrium between MHC alleles were hampered by the lack of high quality reagents for HLA allele typing.…”

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confidence: 99%

HLA‐Cw alleles associated with HLA extended haplotypes and C2 deficiency

et al. 1998

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There are four MHC-linked complement genes, BF, C2, C4A and C4B, that are inherited as single DNA units, known as complotypes. Extended haplotypes were initially defined by studying the distribution of complotypes in relation to HLA-B and HLA-DR loci in Caucasian families. In order to analyze the distribution of HLA-Cw alleles in relation to extended haplotypes, we studied a large panel of MHC homozygous and heterozygous cell lines representing previously described Caucasian-derived extended haplotypes and 14 patients with complete C2 deficiency. HLA alleles were assigned using sequence-specific oligonucleotide probe hybridization (SSOP). Family analysis served to assign haplotypes for heterozygous samples. We found distinctive HLA-Cw alleles for each independent extended haplotype. Their association in each instance was statistically significant. All patients with C2 deficiency carrying the haplotype [HLA-B18, S042, DR2] were associated with HLA-Cw*1203. These conserved allelic combinations may become an important tool for the study of human evolution and may contribute to the expeditious selection of prospective donors in clinical transplantation.

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HLA‐Cw alleles associated with HLA extended haplotypes and C2 deficiency

et al. 1998

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“…In North American Blacks an identical extended haplotype has been described; however, only one-third of the C4A*12 A*QO, C4B*QO, DR3, DQ4 haplotypes were associated with the B42 allele. Also, DR3 belonged commonly to the DR17 split [25,26,27].…”

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confidence: 99%

C4 polymorphism and extended HLA haplotypes in Namibian San and Khoi and in South African Xhosa

Creemers¹,

Toit²

1996

Tissue Antigens

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We studied C4A and C4B polymorphisms and HLA-B and -DR associations in the San, Khoi and Xhosa. C4A and C4B alleles were determined using conventional protein allotyping methods. The C4A*3, C4B*1 haplotype had a high frequency (30-55%) in all populations. The frequency of C4A*3, C4B*Q0 was 7-19%. The C4A*Q0, C4B*1 haplotype was frequent (15%) in the Khoi but very rare in the San (P < 0.001). C4A*12 A*91, C4B*Q0 was frequent in the Xhosa (15%) but rare in the San and Khoi (P < 0.001). Alleles C4A*5 and C4A*6, and the C4B*2 B*92 duplication were only found in the Xhosa. C4A alleles A*4, A*45, A*58, A*12, A*14, A*19 and the C4A*3 A*91 duplication were only found in the San/Khoi population group. In the San, fourteen extended haplotypes were found in a relatively high frequency (2-7%). In the Xhosa, one extended haplotype (B42, C4A*12 A*91, C4B*Q0, DR18) was found in a very high frequency (13%) and was characteristic for this group; five other extended haplotypes were found with a low frequency (< 3%).

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