Age at Onset of LRRK2 p.Gly2019Ser Is Related to Environmental and Lifestyle Factors

ABSTRACT Objectives The effect of environmental and lifestyle factors on patients with LRRK2 (leucine‐rich repeat kinase 2) p.Gly2019Ser (LRRK2 + /PD + ) compared to idiopathic PD (iPD) has yet to be thoroughly investigated. Methods In a homogeneous Tunisian Arab Berber population, we recruited 200 idiopathic PD and 199 LRRK2 p.Gly2019Ser mutation carriers, of whom 142 had PD (LRRK2 + /PD + ) and 57 were unaffected (LRRK2 + /PD − ). Case report form (CRF) questionnaires (motor and non‐motor symptoms) including the Geoparkinson Questionnaire were used to assess environmental and lifestyle factors. Results In LRRK2 + /PD + , tobacco use was significantly associated with a later median age at onset (AAO). The median AAO was 60 years (interquartile range = 52–67.25) for tobacco users, compared to 52 years (interquartile range = 45.25–61) for non‐users ( P = 0.0042 at adjusted α = 0.025). Additionally, we observed an independent but additive effect of black tea consumption and tobacco use. Conclusions Our data suggest that tobacco and black tea have a protective effect on age at onset in LRRK2 + /PD + . © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.