A link between the onset of clinical symptoms and α-synuclein pathology is further supported by studies indicating that a plethora of typical PD premotor signs encompassing olfactory dysfunctions, sleep disorders, cardiovascular dysfunction, and gastrointestinal and urinary abnormalities may still be attributed to α-synuclein accumulation affecting both central and peripheral neuronal cells [14]. The gene discussed is SNCA; the disease is sleep disorder.