SNCA and Parkinson disease: We observed α‐synuclein overexpression through a significant upregulation of SNCA mRNA abundance in cells from patients at the relatively milder end of the EPG5‐related VS spectrum in patient 1 (p.Gln336Arg) and patient 2 (p.Arg1621Gln), as well as in the cell line from patient 3 with EPG5‐related parkinsonism (Fig 5K).