Tags

Type your tag names separated by a space and hit enter

Human MHC class III (Bf, C2, C4) genes and GLO: their association with other HLA antigens and extended haplotypes in the Spanish population.
Tissue Antigens. 1988 Jan; 31(1):14-25.TA

Abstract

C4 allotype frequencies and their combination with factor B and C2 alleles (complotypes) were studied in a sample of the Spanish population in relation to MHC class I, class II and GLO alleles. The shorter genetic distances found for C4 between Spaniards and North Africans and the high frequency of extended HLA haplotypes (GLO 2) HLA-DR3 F1C30 HLA-B18 HLA-Cw5 (HLA-A30) and HLA-DR7 S1C21 HLA-Bw50 HLA-Cw6 are consistent with a paleo-North African ethnic origin (about 20,000 years B.C.) of a part of present Spaniards (Iberians), and with the effect of racial admixture during late Moslem invasions (from the 8th to the 15th century). The complotype null alleles C4A QO and C4B QO may be under natural selection pressure when found in cis position, since they are never in the same haplotype in families. The underestimation of these C4 null alleles' frequencies in unrelated individuals as compared to genotyped families is shown to be a very likely event and a serious hindrance for C4-disease association studies. We have not found any C4 duplications in the Spanish population; this may be due to sample size limitations or to the degree of admixture of our population. Strikingly, no positive linkage disequilibrium between C4A and C4B alleles is detected in unrelated individuals nor in families, although strong associations are maintained among Bf, C2, C4, HLA-A, HLA-B, HLA-C and HLA-DR markers. Assuming that all MHC polymorphisms have reached equilibrium, several explanations are proposed, including the possibility of no, different or additional natural selection mechanisms operating on some MHC class III genes (Bf, C2, C4 alleles combinations for most appropriate C3 convertases), as compared to those affecting class I and class II gene clusters (most advantageous immune response genes sets).

Authors+Show Affiliations

Regueiro JR
Inmunología, Hospital Primero de Octubre, Madrid, Spain.
Arnaiz-Villena A
No affiliation info available

MeSH

AllelesComplement C2Complement C4Complement Factor BEnzyme PrecursorsGene FrequencyGenesGenes, MHC Class IHLA AntigensHaplotypesHumansLactoylglutathione LyaseLyasesMajor Histocompatibility ComplexPhenotypeSpain

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

3341017

Citation

Regueiro, J R., and A Arnaiz-Villena. "Human MHC Class III (Bf, C2, C4) Genes and GLO: Their Association With Other HLA Antigens and Extended Haplotypes in the Spanish Population." Tissue Antigens, vol. 31, no. 1, 1988, pp. 14-25.
Regueiro JR, Arnaiz-Villena A. Human MHC class III (Bf, C2, C4) genes and GLO: their association with other HLA antigens and extended haplotypes in the Spanish population. Tissue Antigens. 1988;31(1):14-25.
Regueiro, J. R., & Arnaiz-Villena, A. (1988). Human MHC class III (Bf, C2, C4) genes and GLO: their association with other HLA antigens and extended haplotypes in the Spanish population. Tissue Antigens, 31(1), 14-25.
Regueiro JR, Arnaiz-Villena A. Human MHC Class III (Bf, C2, C4) Genes and GLO: Their Association With Other HLA Antigens and Extended Haplotypes in the Spanish Population. Tissue Antigens. 1988;31(1):14-25. PubMed PMID: 3341017.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Human MHC class III (Bf, C2, C4) genes and GLO: their association with other HLA antigens and extended haplotypes in the Spanish population. AU - Regueiro,J R, AU - Arnaiz-Villena,A, PY - 1988/1/1/pubmed PY - 1988/1/1/medline PY - 1988/1/1/entrez SP - 14 EP - 25 JF - Tissue antigens JO - Tissue Antigens VL - 31 IS - 1 N2 - C4 allotype frequencies and their combination with factor B and C2 alleles (complotypes) were studied in a sample of the Spanish population in relation to MHC class I, class II and GLO alleles. The shorter genetic distances found for C4 between Spaniards and North Africans and the high frequency of extended HLA haplotypes (GLO 2) HLA-DR3 F1C30 HLA-B18 HLA-Cw5 (HLA-A30) and HLA-DR7 S1C21 HLA-Bw50 HLA-Cw6 are consistent with a paleo-North African ethnic origin (about 20,000 years B.C.) of a part of present Spaniards (Iberians), and with the effect of racial admixture during late Moslem invasions (from the 8th to the 15th century). The complotype null alleles C4A QO and C4B QO may be under natural selection pressure when found in cis position, since they are never in the same haplotype in families. The underestimation of these C4 null alleles' frequencies in unrelated individuals as compared to genotyped families is shown to be a very likely event and a serious hindrance for C4-disease association studies. We have not found any C4 duplications in the Spanish population; this may be due to sample size limitations or to the degree of admixture of our population. Strikingly, no positive linkage disequilibrium between C4A and C4B alleles is detected in unrelated individuals nor in families, although strong associations are maintained among Bf, C2, C4, HLA-A, HLA-B, HLA-C and HLA-DR markers. Assuming that all MHC polymorphisms have reached equilibrium, several explanations are proposed, including the possibility of no, different or additional natural selection mechanisms operating on some MHC class III genes (Bf, C2, C4 alleles combinations for most appropriate C3 convertases), as compared to those affecting class I and class II gene clusters (most advantageous immune response genes sets). SN - 0001-2815 UR - https://www.unboundmedicine.com/medline/citation/3341017/Human_MHC_class_III__Bf_C2_C4__genes_and_GLO:_their_association_with_other_HLA_antigens_and_extended_haplotypes_in_the_Spanish_population_ DB - PRIME DP - Unbound Medicine ER -