KNG1 and multiminicore myopathy: Compared to HC, we observed a significant increase in BK (11.54 ± 2.88 μg/mL vs. 9.75 ± 3.10 μg/mL, p = 0.002, 1a‐1c), des‐Arg9‐BK (0.57 ± 0.12 μg/L vs. 0.45 ± 0.13 μg/L, p < 0.001) and B1R (102.44 ± 26.09 pg/mL vs. 88.09 ± 22.09 pg/mL, p = 0.0023) levels were observed in the serum of patients with MMD.