Deep brain stimulation (DBS) of the internal globus pallidus was effective in 13 patients with drug‐resistant SGCE‐, KMT2B‐, and GNAO1‐related HMDs but did not show significant improvement in one 10‐year‐old boy with a severe PDE10A‐related HMD after 2‐year follow‐up (Table 1, Table S2 in Appendix S1). This evidence concerns the gene KMT2B and hereditary mucoepithelial dysplasia.