Cognitive impairment in carriers of glucocerebrosidase gene mutation in Parkinson disease patients.

Parkinson disease (PD) is the common neurodegenerative disease with motor and numerous non-motor symptoms, including cognitive impairment. Mutation of glucocerebrosidase (GBA) gene is the most common genetic risk factor of sporadic PD. The aim of this study was to assess clinical features of PD associated with GBA mutation. One hundred and thirty-eight PD patients were involved and examined by the movement disorder specialist using several scales including Unified Parkinson Disease Rating Scale (UPDRS) part II and III, Hoehn and Yahr (H&Y) staging, Mini-Mental State Examination (MMSE) and Hamilton Depression Scale (HDS). The exons 8 and 9 of GBA was sequenced and screened for variants. The GBA variants were found in 16 (11.6%) PD patients: N370S mutation in 5 (3.6%) and T369M variant in 11 (7.9%). No significant differences between the group of mutation carriers and non-carriers were found in relation to clinical features except for dementia (MMSE score<26) occurring more often in N370S mutation carriers (60.0% vs 19.6%, p=0.03). The N370S GBA mutation is the risk factor for cognitive impairment in PD patients.