Association of gender and age at onset with glucocerebrosidase associated Parkinson's disease: a systematic review and meta-analysis.

Glucocerebrosidase (GBA) gene has been proved to be a risk factor for the development of Parkinson's disease (PD). However, the gender effect in the prevalence of GBA-associated PD (GBA-PD) is still controversial. And there is no conclusion whether the age at onset (AAO) of PD is different between carriers and non-carriers of GBA. To clarify the association between gender and AAO in GBA-PD, we conducted a systematic review and meta-analysis. PubMed, Web of Science, and Embase were retrieved to obtain potentially related studies. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to determine the association between gender and GBA-PD. And the weighted mean difference (WMD) with 95% CIs was employed to assess the difference of AAO between carriers and non-carriers of GBA. A total of twenty-eight studies involving 16,488 PD patients were included in this meta-analysis. The results showed the prevalence of female patients was higher in GBA-PD [OR: 1.19, (95% CI, 1.07-1.32), P = 0.001]. Meanwhile, GBA carriers had younger age at PD onset than GBA non-carriers [WMD: 2.87, (95% CI, 2.48-3.27), P < 0.001]. Results of subgroup analysis showed the prevalence of women in GBA-PD was higher than men in North American and European PD patients, while the gender difference was not significant in other areas around the world, suggesting an ethnic specificity of gender effect for GBA-PD. Our results indicate the higher female prevalence with ethnic specificity and younger AAO of GBA carriers in GBA-PD.