Rep1 microsatellite length influences non-motor symptoms in early Parkinson's disease.

Long alpha-synuclein gene promoter (Rep1) allele-carriers are linked to higher risk for Parkinson's disease (PD) and faster motor progression. Non-motor symptoms including autonomic, neuropsychiatric, and sleep disorders are common in PD. However, the relationship between Rep1 microsatellite lengths and non-motor symptoms in early PD remains to be elucidated.