A multi-centre clinico-genetic analysis of the VPS35 gene in Parkinson disease indicates reduced penetrance for disease-associated variants - Sharma, M; Ioannidis, JPA; Aasly, JO; Annesi, G; Brice, A; Bertram, L; Bozi, M; Barcikowska, M; Crosiers, D; Clarke, CE; Facheris, MF; Farrer, M; et al. (JOURNAL OF MEDICAL GENETICS, 2012)