SMNDC1 and multiminicore myopathy: RHO guanine nucleotide exchange factor 1 (ARHGEF3), glucoside xylosyltransferase 1 (GXYLT1), speckle-type BTB/POZ protein (SPOP), and survival motor neuron-related splicing factor 30 (SMNDC1) were significantly lower expressed in MMD ECFCs compared to control ECFCs, consistent with the experimental data (Fig. 4).