This interesting study assessed the association of established MS risk variants in 1,162 cases and 2,092 controls in an non-European data-set. HLA-DRB1, HLA-DQB1 and HLA-A alleles were typed using molecular techniques. Single nucleotide polymorphism (SNP) genotyping was conducted for 76 MS-associated SNPs and 52 ancestry SNPs selected throughout the genome.
They found that the following major histocompatibility complex risk alleles were replicated: HLA-DRB1*15:01, HLA-DRB1*03:01, HLA-DRB1*04:05 as well as the African-specific risk allele of HLA-DRB1*15:03. African American people with MS carry the two most prominent susceptibility HLA-DRB1 alleles found in Europeans. The study group confirmed the protective association of HLA-A*02:01. There was no association with any of the HLA-DQB1 alleles and MS.
Overall, MS genetic risk in African Americans only partially overlaps with that of Europeans and could explain the difference of MS prevalence between populations.
Authors: Isobe N, Gourraud PA
Source: Neurology. 2013 Jun 14. [Epub ahead of print]
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