By Ana Espino | Published on April 7, 2026 | 4 min readParkinson’s disease is a major
progressive neurodegenerative disorder affecting more than
8.5 million people
worldwide. Its incidence continues to rise, making it an increasing public
health concern. The disease is characterized by the
progressive degeneration of
dopaminergic neurons in the substantia nigra, along with the accumulation of
α-synuclein
aggregates, leading to neuronal dysfunction.
Clinically, Parkinson’s disease
presents with motor symptoms—including
bradykinesia,
rigidity, and tremor—as
well as often disabling non-motor manifestations such as cognitive impairment
and sleep disorders. These features reflect the complexity of the underlying
pathophysiological mechanisms, which remain only partially understood.
Current treatments, dominated by
levodopa, provide initial symptomatic relief. However, their effectiveness
declines over time, with the emergence of motor
fluctuations and dyskinesias.
Moreover, these approaches do not target the underlying disease mechanisms and
have limited impact on non-motor symptoms.
In this context, there is a
critical need for strategies capable of
slowing—or even modifying—disease
progression. Gene therapy is emerging as an innovative approach aimed at
directly targeting the molecular mechanisms involved, including dopamine production,
neuroprotection, and reduction of α-synuclein.
The aim of this review is to
analyze recent developments in gene therapy for Parkinson’s disease by
evaluating mechanisms of action, clinical outcomes, and limitations, in order
to identify future therapeutic perspectives.
Does gene therapy live up to
its promise?
This review synthesizes data from
preclinical studies and clinical trials assessing various gene therapy
approaches. These methods primarily rely on
viral vectors—particularly
AAV,
lentivirus, and
HSV—to enable targeted gene delivery to the central nervous
system.
Strategies aimed at restoring the
dopaminergic system involve introducing genes involved in dopamine synthesis,
such as
TH, AADC, and GTPCH. Clinical trials have shown
improvements in motor
scores (UPDRS) and good tolerability, although effects are comparable to
placebo in some studies.
Other approaches target neuronal
hyperactivity through the expression of
GAD, increasing
GABA production. Phase
II trials report approximately a
23% improvement in motor scores, confirming a
moderate but significant clinical effect.
Neuroprotection is another major
focus, with the administration of trophic factors such as
GDNF, NRTN, or CDNF.
These strategies increase dopaminergic biomarkers but do not consistently
translate into clinical benefit, particularly in patients at advanced stages.
Therapies targeting genetic
mutations—such as
PINK1, PRKN, or DJ-1—aim to correct mitochondrial
dysfunction. Animal models show
functional improvement and significant
neuroprotection.
Restoring lysosomal function via
GBA1 represents a promising strategy, reducing α-synuclein accumulation and
inflammation, with several clinical trials currently underway.
Finally, reducing
SNCA expression
using RNA interference decreases α-synuclein levels and improves symptoms in
animal models. However, potential
neurotoxicity highlights the need for precise
control of gene expression.
A real hope, still to be
confirmed
Parkinson’s disease remains a
complex neurodegenerative condition with no curative treatment to date. Current
approaches are largely symptomatic and do not
slow disease progression,
underscoring the urgent need for strategies targeting
underlying pathophysiological
mechanisms.
In this context, this review
highlights
gene therapy as a particularly promising approach, with observed
effects on
motor function and certain
neurological biomarkers—suggesting
potential benefits beyond symptomatic control.
Nevertheless, several limitations
still hinder its clinical application. There is
significant variability in
patient responses, likely related to disease heterogeneity and stage
differences. Technical challenges associated with
viral vectors—particularly
regarding targeting, safety, and control of gene expression—remain substantial.
In addition, the
lack of long-term data limits the assessment of sustained
efficacy and potential adverse effects.
Future perspectives rely on the
development of
combined strategies targeting multiple pathways, as well as
optimization of
delivery systems to improve precision and safety.
Better
patient selection, based on genetic and clinical profiles, will also be essential.
Ultimately, gene therapy could become a
cornerstone of personalized medicine,
with the potential to modify the course of Parkinson’s disease.
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About the author – Ana Espino
PhD in Immunology, specialized in Virology
As a scientific writer, Ana is passionate about bridging the gap between research and real-world impact. With expertise in immunology, virology, oncology, and clinical studies, she makes complex science clear and accessible. Her mission: to accelerate knowledge sharing and empower evidence-based decisions through impactful communication.
