MICA-HLA-B haplotype diversity and linkage disequilibrium in a population of Jewish descent from Majorca (the Balearic Islands).
The major histocompatibility complex class I chain-related A (MICA) gene is located 46 kb centromeric of human leukocyte antigen (HLA)-B and is highly polymorphic, similar to HLA genes. This allelic variation may influence the affinity of MICA molecules to their receptor on natural killer, gammadelta T and CD8+ T cells, NKG2D, and the immune response to organ transplantation and disease susceptibility. In the present study, we typed MICA and HLA-B polymorphisms in 95 individuals from a population of Jewish descent (Chuetas) and 195 individuals of Caucasian origin from Majorca (the Balearic Islands). MICA*008, -*004, and -*002 were the most common alleles and accounted for 53 and 60% in Chuetas and Majorcans, respectively. Other common alleles (frequency >5%) were MICA*016, -*009, -*012, -*007, and -*017 in Chuetas and -*009, -*001, and -*018 in Majorcans. We also studied two-locus haplotype diversity and linkage disequilibrium (LD). Both populations presented haplotypes with significant LD that were shared by other Caucasians populations, but we reported particular haplotypes in the Chueta group: MICA*002-HLA-B*38, MICA*016-HLA-B*35, MICA*012-HLA-B*55, and MICA*017-HLA-B*57. These haplotypes were not reported in other studies at high frequencies. In conclusion, the Chueta population presents a particular genetic pool but has affinities with the host population.
Cambra
Ana
A
Immunology Service, Hospital Universitari Son Dureta, Palma de Mallorca, Spain.
Muñoz-Saá
Iván
I
Crespí
Catalina
C
Serra
Antònia
A
Etxagibel
Aitziber
A
Matamoros
Núria
N
Milà
Joan
J
Julià
Maria Rosa
MR
D005787:Gene Frequency; D014644:Genetic Variation; D015235:HLA-B Antigens / Q000235:genetics*; D006239:Haplotypes; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D007585:Jews / Q000235:genetics*; D015810:Linkage Disequilibrium; D011110:Polymorphism, Genetic; D013030:Spain; D044465:White People / Q000235:genetics
D015235:HLA-B Antigens; D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A