Towards a molecular phototyping system for allelic variants of MICA, encoded by polymorphisms in exons 2, 3 and 4 of MHC class I chain-related genes

In this study we have developed a polymerase chain reaction sequence-specif ic primer (PCR-SSP) or phototyping system to analyse the polymorphism oi th e human MICA gene locus. By scrutinising the reported MICA sequence variati ons in exons 2, 3 and 4 which encode the extracellular protein domains, we have selected and tested 20 MICA-specific primer mixes that should discrimi nate between the majority of homozygous and heterozygous combinations of MI CA alleles 001-016. We have tested this scheme on DNA prepared from a large number of well-characterised tissue culture cell lines with previously rep orted MICA nucleotide sequences and found an excellent correlation with the observed PCR-SSP phototypes. We believe that this scheme can also be modif ied to detect new MICA alleles when they are characterised, as well as be i ncorporated into standard phototyping protocols to generate allele and hapl otype profiles of both classical and non-classical HLA gene loci in test DN A samples.