MICA polymorphism in a population from north Morocco, Metalsa Berbers, using sequence-based typing.
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.
Piancatelli
Daniela
D
CNR Istituto per i Trapianti d'Organo e l'Immunocitologia, L'Aquila, Italy. d.piancatelli@itoi.cnr.it
Del Beato
Tiziana
T
Oumhani
Khadija
K
El Aouad
Rajae
R
Adorno
Domenico
D
D000293:Adolescent; D000328:Adult; D000368:Aged; D000483:Alleles; D005260:Female; D005787:Gene Frequency; D005828:Genetics, Population; D015234:HLA-A Antigens / Q000235:genetics; D015235:HLA-B Antigens / Q000235:genetics; D006239:Haplotypes; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009018:Morocco; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA
D015234:HLA-A Antigens; D015235:HLA-B Antigens; D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A