MICA polymorphism in a population from north Morocco, Metalsa Berbers, using sequence-based typing

Hum Immunol. 2005 Aug;66(8):931-6. doi: 10.1016/j.humimm.2005.06.008. Epub 2005 Aug 16.

Abstract

The MICA gene encodes a family of nonclassical major histocompatibility complex class I molecules. Data on MICA polymorphism in different populations are still limited. In the present study, MICA allele frequencies (af) were assessed in 82 unrelated healthy individuals from a Moroccan Berber population named Metalsa (ME) by means of sequence-based typing of exons 2, 3, 4, and 5. In consideration of the linkage disequilibrium existing between MICA and human leukocyte antigen (HLA) class I alleles, MICA/HLA-B, MICA/HLA-Cw, and MICA/HLA-A haplotype frequencies (hf) were estimated. A wide allelic distribution including 16 different MICA alleles was found in ME. The most common MICA alleles were MICA*00801 (af = 0.268), *004 (0.232), *00902 (0.140), *00901 (0.085), and *00901 (0.073). The most common MICA/HLA-B haplotypes were MICA*004-B*4403 and MICA*009-B*50 (hf = 0.113 for both these haplotypes). Some known MICA and HLA-B associations were confirmed in this population. Noteworthy was the high frequency of MICA*009 (af = 0.226); the high frequency of B*50 found in ME (af = 0.114) permitted us to evidence the associations of MICA*00902 with B*5001 (hf = 0.068) or *5002 (hf = 0.045), whereas MICA*00901 was mainly associated with B*5101 (hf = 0.038), which corresponds to the previously described association MICA*009/A6-HLA-B*51. This study extends the previous knowledge on MICA polymorphism to a North African white population and may have implications for disease associations and transplantation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Alleles
  • Female
  • Gene Frequency
  • Genetics, Population*
  • HLA-A Antigens / genetics
  • HLA-B Antigens / genetics
  • Haplotypes
  • Histocompatibility Antigens Class I / genetics*
  • Humans
  • Male
  • Middle Aged
  • Morocco
  • Polymorphism, Genetic*
  • Sequence Analysis, DNA

Substances

  • HLA-A Antigens
  • HLA-B Antigens
  • Histocompatibility Antigens Class I
  • MHC class I-related chain A