LRRK2 and Parkinson disease: Conversely, hyposmia has been reported to be approximately 30% less frequent in Leucine-rich repeat kinase 2 (LRRK2) patients than in idiopathic PD [76,77], while PD patient carriers of a mutation in the glucocerebrosidase gene seem to have impaired olfaction after the appearance of motor symptoms [78].