Autoimmunemechanismsarelikelyinvolvedinthepathogenesisofidiopathicdilatedcardiomyopathy(IDC)andcomponentsofMHCmayserveasmarkersforthepropensitytodevelopimmune-mediatedmyocardialdamage.ThisstudywasconductedtoinvestigatethepossibleassociationbetweenHLA-DQA1,-DQB1allelesandIDCinHanpopulationfromnorthernChinabyusingPCR-basedsequence-specificprimer(PCR-SSP)techniqueforHLAgenotyping.Among68unrelatedIDCpatients,4probandsofIDCpedigreesand100healthycontrols,wefoundthattheallelesofHLA-DQA1*0501andHLA-DQB1*0303conferredsusceptibilitytoIDCwhileHLA-DQA1*0201andHLA-DQB1*0502,*0504alleleswereinnegativeassociationwithIDC.Theserineatposition57(SER57)intheexonofHLA-DQB1*0502and*0504wasconfirmedinourexperimentasamarkerforresistancetoIDC.TheresultssuggestthatHLA-DQpolymorphismmaybeinvolvedinthepathogenesisofIDC.