Effect of GBA gene variants on clinical characteristics of dementia with Lewy bodies: a review and meta-analyses

Abstract

Glucocerebrosidase (GBA) gene may be a risk factor for dementia with Lewy bodies (DLB). However, due to the small number of existing studies and the small sample size of previous investigations, it is necessary to conduct objective and quantitative analyses of the association between GBA variants and DLB. There is no consensus regarding the relationship between GBA and the clinical characteristics of DLB. Therefore, we conducted multiple systematic reviews and meta-analyses with a particular focus on the age of onset, sex, and cognitive impairment. PubMed, Cochrane, and EMBASE databases were searched to retrieve related studies. The odds ratios and 95% confidence interval were calculated to determine the association between GBA and DLB and between GBA and the clinical characteristics of DLB. Our meta-analysis confirmed that the GBA variant rate was significantly higher in the DLB group than in the control group, as were the variant rates of L444P, N370S, and E326K, whereas the variant rate of T369M showed no significant difference between the groups. Furthermore, the relevant literature was summarised again for meta-analyses. The GBA variant group had a younger age of onset and lower Montreal Cognitive Assessment score than the GBA non-variant group in DLB patients. GBA variants do not differ between sexes in DLB patients. GBA variants increased the risk of DLB, especially N370S, E326K, and L444P which are strongly associated with DLB, but T369M was not. Patients harbouring GBA variants have an earlier age of onset, more severe cognitive impairment, and rapid symptom progression; however, sex is irrelevant in DLB.