The results indicated that the frequency of thyroid diseases, including Graves’ disease (GD) and Hashimoto thyroiditis (HT), is high in HLA-DRB1*04:10-positive MMD patients compared with that in HLA-DRB1*04:10-negative MMD patients (frequency 23.1% vs. 4.1% in the control group; P = 0.029). Here, HLA-DRB1 is linked to multiminicore myopathy.