title: Seronegative peripheral arthritis in B27 positive monozygotic twin sisters.
mesh_terms: D000328:Adult; D001168:Arthritis / Q000175:diagnosis / Q000235:genetics* / Q000276:immunology; D004200:Diseases in Twins; D005260:Female; D006680:HLA Antigens / Q000032:analysis*; D015796:HLA-B27 Antigen; D006801:Humans; D011247:Pregnancy; D012698:Serologic Tests; D014427:Twins; D014430:Twins, Monozygotic
chemical_list: D006680:HLA Antigens; D015796:HLA-B27 Antigen