Sequencing based typing for genetic polymorphisms in exons, 2, 3 and 4 of the MICA gene.
We have established a sequencing based typing (SBT) method for detection of genetic polymorphism in the exon 2 to 4 domains of the major histocompatibility complex (MHC) class I chain-related gene A (MICA) and applied it to allele typing of 130 healthy Japanese individuals. A 2.2-kb segment including exons 2, 3 and 4 of the MICA gene was amplified by a pair of generic primers followed by cycle sequencing using exon-specific nested primers. In total, 8 alleles were observed in a Japanese population and the most frequent allele was MICA008 with the gene frequency of 30.8%. MICA009 was the second most frequent (16.5%), while the rarest one was MICA007 (1.2%). MICA alleles displayed strong linkage equilibria with HLA-B antigens (i.e. MICA008 with B7, B48, B60 and B61; MICA009 with B51 and B52; MICA002 with B35, B39, B58 and B67; MICA004 with B44, MICA007 with B13 and B27; MICA010 with B46, B62 and B48, MICA012 with B54, B55, B56 and B59; MICA019 and B70, B71 and B62). Recently, the B48 haplotype has been reported to lack the entire MICA gene by a large-scale deletion in a Japanese population. Among 8 serologically B48 homozygous individuals, 4 were found to represent this MICA null allele as assessed by no polymerase chain reaction (PCR) amplification using MICA-specific primers, while the remaining four possessed the intact MICA gene with MICA008 or MICA010.
Katsuyama
Y
Y
Department of Pharmacy, Shinshu University Hospital, Matsumoto, Nagano, Japan.
Ota
M
M
Ando
H
H
Saito
S
S
Mizuki
N
N
Kera
J
J
Bahram
S
S
Nose
Y
Y
Inoko
H
H
D044466:Asian People / Q000235:genetics; D004252:DNA Mutational Analysis; D005091:Exons / Q000235:genetics*; D005787:Gene Frequency; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D007564:Japan; D008565:Membrane Proteins / Q000235:genetics; D011110:Polymorphism, Genetic / Q000235:genetics*
D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A; D008565:Membrane Proteins