¶ MDS 2026: Genetics and Biomarkers in Movement Disorders
Congress: International Congress of Parkinson's Disease and Movement Disorders (MDS 2026)
Location: Seoul, South Korea
Dates: October 4-8, 2026
This page synthesizes the latest research on genetics and biomarkers in movement disorders presented at MDS 2026, with a focus on Parkinson's disease (PD) and related synucleinopathies.
MDS 2026 featured landmark presentations on:
- Genetic modifiers of PD risk and progression (GBA, LRRK2, SNCA, VPS35, ATP13A2)
- Alpha-synuclein seeding assays reaching clinical validation thresholds
- Tau PET tracers showing diagnostic utility in atypical parkinsonism
- Genetic testing guidelines updated for clinical practice
- Polygenic risk scores moving toward clinical implementation
Glucocerebrosidase (GBA) variants remain the most significant genetic risk factor for PD, with prevalence estimates of 5-10% in PD populations.
| Variant |
Risk Category |
Penetration |
Clinical Features |
| N370S |
Moderate risk |
~10% |
Earlier onset, cognitive decline |
| E326K |
Moderate risk |
~8% |
Faster progression |
| L444P |
High risk |
~15% |
Severe phenotype |
| Complex |
High risk |
~20% |
Rapid progression |
Key findings from MDS 2026:
-
GBA-PD as a distinct entity: Growing consensus that GBA-PD represents a distinct clinical subtype with:
- Faster cognitive decline
- Earlier autonomic dysfunction
- Distinct sleep architecture (RBD precedes motor symptoms)
- Higher burden of non-motor symptoms
-
Therapeutic implications:
- Ambroxol showing promise in restoring GCase activity
- Gene therapy approaches (AAV-GBA) in clinical development
- Substrate reduction therapy trials ongoing
-
Genetic counseling: New consensus guidance for GBA variant disclosure in PD patients
LRRK2 remains the most common monogenic cause of PD, with the G2019S variant accounting for ~5% of sporadic PD in certain populations.
LRRK2-associated PD characteristics:
- Typical PD phenotype with tremor dominance
- Good levodopa response
- Intermediate progression rate
- Non-motor symptoms similar to idiopathic PD
Therapeutic targeting:
- LRRK2 kinase inhibitors in Phase 2/3 trials
- ASO-based approaches in development
- Gene therapy for mutant allele reduction
Alpha-synuclein gene (SNCA) duplications and point mutations cause highly penetrant PD.
Key variants:
- A53T (SNCAm): Early onset (~45 years), rapid progression, prominent autonomic dysfunction
- A30P: Incomplete penetrance, variable phenotype
- Triplication: Early onset, severe dementia
| Gene |
Variant |
Inheritance |
Key Features |
| VPS35 |
D620N |
Autosomal dominant |
Late onset, good response to levodopa |
| ATP13A2 |
Loss-of-function |
Autosomal recessive |
Juvenile parkinsonism, dementia |
| PRKN |
Various |
Autosomal recessive |
Early onset, dystonia |
| PINK1 |
Various |
Autosomal recessive |
Early onset |
| DJ-1 |
Various |
Autosomal recessive |
Early onset |
The landscape of alpha-synuclein biomarkers has transformed with the advent of seed amplification assays (SAAs).
- Decreased in PD vs. controls (sensitivity ~70%)
- Lacks specificity for distinguishing PD from other synucleinopathies
- Increased in PD, MSA, DLB
- Higher levels correlate with disease severity
- Sensitivity: 85-90% for PD
- Specificity: 70-80% vs. controls
Real-time quaking-induced conversion (RT-QuIC) and related technologies have achieved clinical-grade performance:
| Assay |
Sensitivity (PD) |
Specificity |
Status |
| RT-QuIC (CSF) |
87-95% |
90-95% |
CLIA validation |
| PMCA (CSF) |
88-96% |
92-98% |
Clinical implementation |
| SynuLight (blood) |
80-85% |
85-90% |
Research use |
MDS 2026 highlights:
- Multi-center validation showing consistent performance
- Ability to distinguish PD from MSA (lower seeding in MSA)
- Pre-motor detection in at-risk populations (RBD, GBA carriers)
Emerging technologies for blood-based detection:
- Plasma pSer129 α-syn: High correlation with CSF levels
- Exosomal α-syn: Disease-specific signatures
- Cell-free DNA: Methylation patterns indicating neuronal loss
¶ 3.1 Current Tracer Landscape
| Tracer |
Target |
Utility in Parkinsonism |
| [^18F]Flortaucipir (APN1607) |
3R/4R tau |
PSP > CBD > PD |
| [^18F]APN-2317 |
4R tau |
PSP specificity |
| [^18F]PI-2620 |
4R tau |
CBS/PSP distinction |
Progressive Supranuclear Palsy (PSP):
- High sensitivity (85-90%) for tau deposition
- Pattern: Brainstem, globus pallidus, subtalamic nucleus
- Correlates with disease severity
Corticobasal Syndrome (CBS):
- Variable uptake depending on underlying pathology
- Asymmetric pattern typical
Parkinson's Disease:
- Minimal tau binding in early stages
- May appear in advanced disease (Braak stage 5-6)
Tau PET assists in distinguishing:
- PSP from PD with high accuracy
- CBS from AD
- Tau-positive vs. tau-negative parkinsonism
Tier 1 (should be offered to all PD patients):
- GBA sequencing (full gene)
- LRRK2 G2019S (population-specific)
- SNCA (dose and point mutations)
Tier 2 (if Tier 1 negative, early onset, or family history):
Tier 3 (research/selective):
- Genome-wide panels
- Whole exome sequencing
The North American PD GENEration initiative has enrolled >10,000 participants with the following findings:
- 15% carry a pathogenic/likely pathogenic variant
- 6% GBA variants (highest yield)
- 3% LRRK2 variants
- 2% other mendelian genes
New consensus guidance emphasizes:
- Pre-test counseling about implications for patients and family
- Variant classification using standardized criteria
- Return of results with multidisciplinary support
- Cascade testing for at-risk relatives (patient choice)
Adapted from Alzheimer's disease, the AT(N) system applied to parkinsonism:
| Component |
PD |
MSA |
PSP |
CBS |
| A (α-synuclein) |
+ |
+ |
- |
+/- |
| T (tau PET) |
- |
- |
+++ |
++ |
| N (neurodegeneration) |
++ |
++ |
+++ |
+++ |
This framework enables biomarker-based classification for clinical trials.
- Multi-analyte panels: Combining α-syn, tau, NFL, and genetic scores
- Digital biomarkers: Wearable-derived metrics correlating with progression
- Neurofilament light chain (NfL): Validation across parkinsonian disorders
- Polygenic risk scores: Integration into clinical risk assessment
- Enrichment strategies: Using biomarkers to select patient subgroups
- Disease modification endpoints: Biomarker changes as surrogate endpoints
- Stratification: Genetic and biomarker-based patient stratification
This page was created from MDS 2026 content synthesis. For the latest updates, check the MDS Congress website.