SNCA Gene Variants and Mutations

SNCA Gene Variants and Mutations

The SNCA (Synuclein Alpha) gene encodes alpha-synuclein, a protein critically involved in synaptic function and implicated in the pathogenesis of Parkinson's disease and related neurodegenerative disorders.

Overview

| Property | Value | [@genetic]
|----------|-------| [@update]
| Gene Symbol | SNCA | [@gene]
| Full Name | Synuclein Alpha |
| Chromosomal Location | 4q22.1 |
| NCBI Gene ID | 6622 |
| OMIM | [163890](https://www.omim.org/entry/163890) |
| Ensembl ID | ENSG00000145335 |
| UniProt ID | [P37840](https://www.uniprot.org/uniprotkb/P37840) |
| Inheritance | Autosomal Dominant |

Function

Alpha-synuclein is a natively unfolded protein primarily localized to presynaptic terminals. Its normal functions include:

• Synaptic vesicle regulation: Alpha-synuclein modulates synaptic vesicle pooling and neurotransmitter release
• Membrane interaction: The protein binds to lipid membranes, potentially regulating vesicle trafficking
• Antioxidant function: Alpha-synuclein may protect [neurons](/entities/neurons) from oxidative stress
• Chaperone activity: The protein has molecular chaperone properties, aiding protein folding

Alpha-synuclein exists in multiple forms:

• Monomeric: Unfolded, cytosolic form
• Oligomeric: Small aggregates (toxic intermediate)
• Fibrillar: Forms Lewy bodies in disease states

Disease Associations

Primary Diseases

...

SNCA Gene Variants and Mutations

The SNCA (Synuclein Alpha) gene encodes alpha-synuclein, a protein critically involved in synaptic function and implicated in the pathogenesis of Parkinson's disease and related neurodegenerative disorders.

Overview

| Property | Value | [@genetic]
|----------|-------| [@update]
| Gene Symbol | SNCA | [@gene]
| Full Name | Synuclein Alpha |
| Chromosomal Location | 4q22.1 |
| NCBI Gene ID | 6622 |
| OMIM | [163890](https://www.omim.org/entry/163890) |
| Ensembl ID | ENSG00000145335 |
| UniProt ID | [P37840](https://www.uniprot.org/uniprotkb/P37840) |
| Inheritance | Autosomal Dominant |

Function

Alpha-synuclein is a natively unfolded protein primarily localized to presynaptic terminals. Its normal functions include:

• Synaptic vesicle regulation: Alpha-synuclein modulates synaptic vesicle pooling and neurotransmitter release
• Membrane interaction: The protein binds to lipid membranes, potentially regulating vesicle trafficking
• Antioxidant function: Alpha-synuclein may protect [neurons](/entities/neurons) from oxidative stress
• Chaperone activity: The protein has molecular chaperone properties, aiding protein folding

Alpha-synuclein exists in multiple forms:

• Monomeric: Unfolded, cytosolic form
• Oligomeric: Small aggregates (toxic intermediate)
• Fibrillar: Forms Lewy bodies in disease states

Disease Associations

Primary Diseases

Parkinson's Disease (PD) - SNCA was the first gene linked to familial PD

Lewy Body Dementia (DLB) - Characterized by Lewy bodies containing alpha-synuclein

Multiple System Atrophy (MSA) - Another synucleinopathy with oligodendroglial inclusions

Parkinson's Disease with Dementia

Key Pathogenic Mutations

| Mutation | Effect | Phenotype | Discovery |
|----------|--------|-----------|-----------|
| A53T (p.Ala53Thr) | Accelerated aggregation | Early-onset PD (familial) | Polymeropoulos et al., 1997 |
| A30P (p.Ala30Pro) | Reduced membrane binding | Familial PD | Krüger et al., 1998 |
| E46K (p.Glu46Lys) | Enhanced aggregation | Familial PD with dementia | Zarranz et al., 2004 |
| H50Q | Modified aggregation | PD | Appel-Cresswell et al., 2013 |
| G51D | Altered aggregation | PD with brainstem pathology | Lesage et al., 2013 |
| A53E | Altered aggregation | MSA-like phenotype | Pasanen et al., 2014 |

Multiplications

• SNCA duplication: Causes autosomal dominant PD
• SNCA triplication: Causes early-onset PD with rapid progression (Parkinsonism-Dementia Complex of Guam)

Pathogenic Mechanisms

• Lewy body formation: Abnormal aggregation of alpha-synuclein into insoluble fibrils
• Synaptic dysfunction: Loss of normal protein function disrupts neurotransmitter release
• Mitochondrial dysfunction: Alpha-synuclein toxicity affects mitochondrial quality control
• Neuroinflammation: Aggregates activate [microglia](/cell-types/microglia-neuroinflammation), promoting neuroinflammation

Expression

Alpha-synuclein is predominantly expressed in the nervous system:

• Substantia nigra - Dopaminergic neurons (most vulnerable in PD)
• [Cortex](/brain-regions/cortex) - Especially in regions affected in DLB
• [Hippocampus](/brain-regions/hippocampus) - Involved in memory impairment
• Hypothalamus and amygdala
• Peripheral nervous system - Including enteric nervous system

Expression is highest in presynaptic terminals of excitatory neurons.

Therapeutic Implications

Current Strategies

• Immunotherapies: Anti-alpha-synuclein antibodies (e.g., cinpanemab, prasinezumab)
• Small molecule inhibitors: Compounds preventing aggregation
• Gene therapy: siRNA approaches to reduce SNCA expression
• Vaccination: Active immunization against alpha-synuclein

Research Directions

• Protein clearance enhancement: Boosting [autophagy](/entities/autophagy) and proteasome function
• Mitochondrial protection: Targeting alpha-synuclein-induced mitochondrial defects
• Synaptic restoration: Compounds promoting synaptic function recovery
• biomarker development: Alpha-synuclein as a diagnostic biomarker

Cross-References

• [Alpha-Synuclein-Targeting Therapies](/therapeutics/alpha-synuclein-targeting-therapies) - Current treatment approaches
• [Parkinson's Disease](/diseases/parkinsons-disease) - Clinical features and pathogenesis
• [Lewy Body Dementia](/diseases/lewy-body-dementia) - DLB disease mechanism
• [Synucleinopathies](/mechanisms/synucleinopathies) - Overview of alpha-synuclein diseases

Key Publications

[Polymeropoulos et al., Mutation in the alpha-synuclein gene identified in families with Parkinson's disease (1997)](https://doi.org/10.1126/science.276.5321.2045)

[Spillantini et al., Alpha-synuclein in Lewy bodies (1997)](https://doi.org/10.1038/388839a0)

[Zarranz et al., The new mutation, E46K, of alpha-synuclein causes Parkinson and Lewy body dementia (2004)](https://doi.org/10.1002/ana.1080)

[Bridi & Hirth, Mechanisms of alpha-Synuclein Induced Neurodegeneration in Parkinson's Disease (2018)](https://doi.org/10.3389/fnins.2018.00090)

See Also

• [SNCA Gene](/genes/snca) — Alpha-synuclein gene
• [Alpha-Synuclein](/proteins/alpha-synuclein) — Synuclein protein
• [Parkinson's Disease](/diseases/parkinsons-disease) — Primary synucleinopathy
• [Dementia with Lewy Bodies](/diseases/dementia-with-lewy-bodies) — Synucleinopathy

External Links

• [PdGene: SNCA](https://www.pdgene.org/)
• [PubMed: SNCA Variants](https://pubmed.ncbi.nlm.nih.gov/)

Recent Research (2024-2026)

This section highlights recent publications relevant to this disease.

• [How to discover novel genes that cause Parkinson's disease.](https://pubmed.ncbi.nlm.nih.gov/41791140/) (2026 Mar 5) - Current opinion in neurobiology
• [Genetic risk loci for Parkinson's disease and dementia in a large-scale population-based Taiwanese cohort (TPMI).](https://pubmed.ncbi.nlm.nih.gov/41810385/) (2026 Mar) - The Lancet regional health. Western Pacific
• [An update on the monogenic causes of Parkinson's disease: Impact on patient stratification and personalised medicine.](https://pubmed.ncbi.nlm.nih.gov/41759745/) (2026 Feb 26) - Ageing research reviews
• [Gene therapy targeting synaptopathy linked with Alzheimer's and Parkinson's disease.](https://pubmed.ncbi.nlm.nih.gov/41730496/) (2026 Feb 21) - Neuroscience
• [The genetic architecture of Parkinson's disease in Mexico: a systematic review.](https://pubmed.ncbi.nlm.nih.gov/41798285/) (2026) - Frontiers in aging neuroscience

References