We conducted a screening of the MHC region for 1,536 single nucleotide polymorphisms ( SNPs ) and the deletion of the C4A gene in a SLE case-control study ( 380 cases , 765 age-matched controls ) nested within the prospective Black Women 's Health Study .
O O O O O O B-GeneOrGeneProduct O O O O O O O O O O O O O O B-GeneOrGeneProduct O O O B-DiseaseOrPhenotypicFeature O O O O O O O O O O O O O O O B-OrganismTaxon O O O O