HLA haplotype can indeed explain some missintrerpreted associations such as narcolepsy, where an apparent association with HLA-DRB1*15 was later found to be actually attributed to an HLA-DQ allele in the haplotype, HLA-DQB1*0602, which is in close linkage disequilibrium with the hypocretin receptor 2 gene. Linkage disequilibrium has been implicated in hereditary hemochromatosis, where an apparent association with HLA-A alleles was later determined to be actually due to two point mutations in a non-classical class I HLA gene, HFE, that are found in linkage disequilibrium with HLA-A3 and HLA-A29 alleles. However, both haplotype-based association and linkage disequilibrium merely direct the blame at another gene and do not provide testable hypothesis to explain the pathogenic mechanism of HLA molecules in disease aetiology.
No comments:
Post a Comment