GBA Mutations Are Associated With Earlier Onset and Male Sex in Dementia With Lewy Bodies.

BACKGROUND: Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are Lewy body diseases characterized by similar pathological features. Several studies have shown a relation between alterations in the glucocerebrosidase gene (GBA) and the development of LB diseases. Here, we explored the role of GBA mutations in Spanish DLB patients. METHODS: GBA mRNA sequences were analyzed in a neuropathological (50 DLB, 43 PD, and 34 control brains) and in a clinical cohort (47 DLB patients and 131 unaffected individuals). RESULTS: Sixteen GBA mutation carriers were identified, 5 of which were brains with pure DLB. The most common mutation, E326K, was strongly associated with pure DLB and PD with dementia. GBA mutations were overrepresented in men and associated with earlier DLB onset. CONCLUSIONS: GBA mutations are also an important risk factor for DLB development in the Spanish population, are associated with earlier disease onset, and are more prevalent in men. © 2015 International Parkinson and Movement Disorder Society.

Glucocerebrosidase mRNA is Diminished in Brain of Lewy Body Diseases and Changes with Disease Progression in Blood.

Parkinson disease (PD) and dementia with Lewy bodies (DLB) are Lewy body diseases characterized by abnormal alpha-synuclein deposits and overlapping pathological features in the brain. Several studies have shown that glucocerebrosidase (GBA) deficiency is involved in the development of LB diseases. Here, we aimed to find out if this deficiency starts at the transcriptional level, also involves alternative splicing, and if GBA expression changes in brain are also detectable in blood of patients with LB diseases. The expression of three GBA transcript variants (GBAtv1, GBAtv2 and GBAtv5) was analyzed in samples from 20 DLB, 25 PD and 17 control brains and in blood of 20 DLB, 26 PD patients and 17 unaffected individuals. Relative mRNA expression was determined by real-time PCR. Expression changes were evaluated by the ΔΔCt method. In brain, specific expression profiles were identified in the temporal cortex of DLB and in the caudate nucleus of PD. In blood, significant GBA mRNA diminution was found in both DLB and PD patients. Early PD and early-onset DLB patients showed lowest GBA levels which were normal in PD patients with advanced disease and DLB patients who developed disease after 70 years of age. In conclusion, disease group specific GBA expression profiles were found in mostly affected areas of LBD. In blood, GBA expression was diminished in LB diseases, especially in patients with early onset DLB and in patients with early PD. Age of disease onset exerts an opposite effect on GBA expression in DLB and PD.