This condition is widely recognised as an early stage of alpha‐synuclein‐related neurodegenerative diseases, which include Parkinson's disease (PD), dementia with Lewy bodies (DLB) and multiple system atrophy (MSA) (Galbiati et al. 2019; Högl et al. 2022; Postuma et al. 2019; Stefani, Trenkwalder, et al. 2023). The gene discussed is SNCA; the disease is Parkinson disease.