dc.description.abstract |
The following comprises a short summary of this clinical observation study including the objective, the applied methods and results as well as the discussion.
A common disease such as Parkinson's disease, which is now understood as a
systemic disease and goes far beyond pure motor disturbance, is clearly associated with the rare lysosomal disorder Gaucher’s disease. At first glance, GD has
little in common with the second most frequent neurodegenerative disease worldwide. Nevertheless, the genetic origin of this compound is based on mutations in
the GBA gene that lead to an increased risk of PD. Profound acknowledgement
of prodromal and clinical symptoms of PDGBA as well as of the progression characteristics of this PD subgroup is of essential importance.
Otherwise, one will not be able at all to detect subjects with the most relevant risk
factor for PD and – as the next step – these subjects at risk for PD might not be
included in clinical and experimental trials. This, however, is the only way to hopefully expand and deepen the current understanding of the underlying mechanisms on how GBA mutations exactly contribute to PD pathology. Based on these
required investigations, the development of promising therapeutic options, that
go far beyond the present symptomatic level, are conceivable and are expected
to slow down or even stop PD progression in the future.
Therefore, a clinical phenotyping of GBA patients was performed in this study. It
revealed that the PDGBA group presented not significantly different from the PDIdiopathic group at the beginning of the 3-year period regarding motor and non-motor
performance. However, at time of the examination in 2013, the PDGBA group was
affected more severely than the comparison group: motor and cognitive impairment had worsened more rapidly. Moreover, higher doses of dopaminergic drugs
were required, and H&Y disease stages reflected a faster progression of PDGBA
to one PD-milestone that can be life-changing for PD patients: the endpoint of
postural instability. Further, higher mortality rates for PDGBA patients were demonstrated in this study.
Epigenetic and environmental factors may seem to play a relevant role in this
subgroup of PD, as well as complex gene-gene interactions. Theories, attempting
to explain the underlying pathology, range from the causal linkage of common
diseases with common genetic variants (CDCV hypothesis) to the currently more
probable assumption that common diseases, such as Parkinson's disease, are
caused by a variety of singular and separately rare variants (CDRV). At the cellular level, moreover, several approaches are pursued, including the pathological
interaction of GCase and α-syn, the impairment of lysosomal clearance, dysfunctional lipid metabolism, disturbances in the area of the proteasome as well as
deficits in mitochondrial function.
The primary background of this prospective study was to contribute to a better
understanding of this neurodegenerative disease by phenotypically characterizing the subtype PDGBA. This is of crucial importance for following steps as to be
able to make a diagnosis at a preferably early disease stage and thus, to prevent
disease-associated and irreversibly neuronal cell loss by means of future disease-modifying, targeted therapies. Currently, promising therapeutic studies are
in progress with the aim of increasing GCase activity or alternatively, minimizing
its pathogenic substrate glucosylceramide. |
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