title: Letter: Normal frequency of HL-A B27 in aortic insufficiency.
mesh_terms: D001022:Aortic Valve Insufficiency / Q000276:immunology*; D006680:HLA Antigens / Q000032:analysis*; D006649:Histocompatibility Antigens / Q000032:analysis*; D006801:Humans
chemical_list: D006680:HLA Antigens; D006649:Histocompatibility Antigens