PSP Genetic Variants

PSP Genetic Variants

Introduction

Progressive Supranuclear Palsy (PSP) is a tauopathy characterized by progressive postural instability, vertical supranuclear gaze palsy, and cognitive impairment. Genetic studies have identified strong associations between PSP and variants in the MAPT (microtubule-associated protein tau) gene, particularly the H1 haplotype, which accounts for a significant portion of genetic risk. Specific pathogenic mutations in MAPT also cause familial PSP. [@eating]

Overview

PSP is a 4-repeat tauopathy with the following genetic architecture: [@pick]

• MAPT H1 haplotype: Major risk factor, ~40% of genetic susceptibility
• Specific MAPT mutations: Cause familial PSP (P301L, ΔN296, etc.)
• Other risk genes: STX6, MOBP, EIF2AK3

Major Genetic Variants

MAPT H1 Haplotype

The MAPT gene has two major haplotypes, H1 and H2. The H1 haplotype is overrepresented in PSP patients: [@spikeid]

• Mechanism: The H1 haplotype has increased expression of 3R and 4R tau isoforms
• Risk: H1/H1 genotype increases PSP risk by 3-5 fold compared to H1/H2
• Prevalence: >95% of PSP patients are H1/H1

The H1 haplotype contains several single nucleotide polymorphisms (SNPs) that tag the risk allele: [@genomewide]

• rs1800547
• rs242557
• rs2471738

MAPT P301L Mutation

The P301L mutation in MAPT is one of the most common pathogenic mutations causing familial PSP: [@acetylation]

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PSP Genetic Variants

Introduction

Progressive Supranuclear Palsy (PSP) is a tauopathy characterized by progressive postural instability, vertical supranuclear gaze palsy, and cognitive impairment. Genetic studies have identified strong associations between PSP and variants in the MAPT (microtubule-associated protein tau) gene, particularly the H1 haplotype, which accounts for a significant portion of genetic risk. Specific pathogenic mutations in MAPT also cause familial PSP. [@eating]

Overview

PSP is a 4-repeat tauopathy with the following genetic architecture: [@pick]

• MAPT H1 haplotype: Major risk factor, ~40% of genetic susceptibility
• Specific MAPT mutations: Cause familial PSP (P301L, ΔN296, etc.)
• Other risk genes: STX6, MOBP, EIF2AK3

Major Genetic Variants

MAPT H1 Haplotype

The MAPT gene has two major haplotypes, H1 and H2. The H1 haplotype is overrepresented in PSP patients: [@spikeid]

• Mechanism: The H1 haplotype has increased expression of 3R and 4R tau isoforms
• Risk: H1/H1 genotype increases PSP risk by 3-5 fold compared to H1/H2
• Prevalence: >95% of PSP patients are H1/H1

The H1 haplotype contains several single nucleotide polymorphisms (SNPs) that tag the risk allele: [@genomewide]

• rs1800547
• rs242557
• rs2471738

MAPT P301L Mutation

The P301L mutation in MAPT is one of the most common pathogenic mutations causing familial PSP: [@acetylation]

• Inheritance: Autosomal dominant
• Penetrance: High (~90% by age 60)
• Phenotype: Classic PSP phenotype with early onset
• Mechanism: Mutation promotes tau aggregation and reduces microtubule binding

MAPT ΔN296 (Splice Site) Mutation

This mutation affects tau exon 10 splicing:[^6]

• Effect: Increases 4R tau isoform production
• Phenotype: PSP phenotype with prominent supranuclear gaze palsy
• Family history: Often autosomal dominant

Other MAPT Mutations in PSP

• P301S: Rare mutation with PSP phenotype[^7]
• K369I: Reported in families with PSP features[^7]
• R5L: Associated with PSP in some families[^7]

Non-MAPT Genetic Risk Factors

STX6 (Syntaxin 6)

Genome-wide association studies (GWAS) have identified STX6 as a risk gene for PSP:[^8]

• Function: Involved in vesicle trafficking
• Mechanism: May affect tau secretion or propagation
• Effect size: Modest odds ratio (~1.2)

MOBP (Myelin-Associated Oligodendrocyte Basic Protein)

MOBP variants are associated with PSP risk:[^9]

• Function: Myelin maintenance in the brain
• Mechanism: May affect white matter integrity

EIF2AK3 (PERK)

Variants in EIF2AK3, encoding the PERK protein involved in the [unfolded protein response](/entities/unfolded-protein-response):[^10]

• Function: ER stress response
• Mechanism: May affect tau processing

Disease Mechanisms

Tau Dysfunction in PSP

The genetic variants in MAPT lead to tau dysfunction:[^11][^12]

Hyperphosphorylation: Increased tau kinase activity leads to abnormal tau phosphorylation

Aggregation: Phosphorylated tau forms neurofibrillary tangles

Microtubule dysfunction: Tau normally stabilizes microtubules; loss of function disrupts axonal transport

Tau spreading: Pathological tau may spread between [neurons](/entities/neurons) via synaptic connections

H1 Haplotype Mechanism

The H1 haplotype likely increases risk through:[@pick][@spikeid]

• Increased expression of 4R tau (exon 10 inclusion)
• Altered splicing efficiency
• Promoter activity differences

Clinical Implications

Genetic Testing

Genetic testing for PSP is considered in:[^13]

• Early-onset patients (<50 years)
• Patients with family history
• Atypical presentations

Testing typically includes:

• MAPT haplotype analysis
• Targeted MAPT mutation screening

Genetic Counseling

• Autosomal dominant inheritance for mutations
• Variable penetrance for risk alleles
• Implications for family members

Therapeutic Implications

Tau-targeted therapies: Anti-tau antibodies, tau aggregation inhibitors[^14]

Gene therapy: AAV-based MAPT silencing[^15]

Small molecule inhibitors: Tau phosphorylation inhibitors[^14]

See Also

• [Progressive Supranuclear Palsy](/diseases/progressive-supranuclear-palsy)
• [MAPT Gene](/genes/mapt)
• [Tau Protein](/proteins/tau)
• [Atypical Parkinsonism Genetic Variants](/diseases/atypical-parkinsonism-genetic-variants)
• [Tauopathies](/mechanisms/tauopathies)

Background

The study of Psp Genetic Variants has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

External Links

• [PubMed](https://pubmed.ncbi.nlm.nih.gov/) - Biomedical literature
• [Alzheimer's Disease Neuroimaging Initiative](https://adni.loni.usc.edu/) - Research data
• [Allen Brain Atlas](https://brain-map.org/) - Brain gene expression data

CBS/PSP Cross-Link Hub

Use this navigation hub to connect disease phenotype, biomarkers, mechanisms, and intervention evidence for corticobasal syndrome (CBS) and progressive supranuclear palsy (PSP).

Core Diseases

• [Progressive Supranuclear Palsy (PSP)](/diseases/progressive-supranuclear-palsy)
• [Corticobasal Syndrome (CBS)](/diseases/corticobasal-syndrome)
• [Corticobasal Degeneration (CBD)](/diseases/corticobasal-degeneration)
• [PSP Genetic Variants](/diseases/psp-genetic-variants)

Mechanistic Pathways

• [4R Tauopathy Molecular Mechanisms](/mechanisms/4r-tauopathy-mechanisms)
• [Cortisol-Tau Pathway: From Chronic Stress to Tauopathy](/mechanisms/cortisol-tau-pathway)
• [Gut-Brain Axis in Tauopathy](/mechanisms/gut-brain-axis-tauopathy)
• [Neuroinflammation Pathway](/mechanisms/neuroinflammation-pathway)
• [Mitochondrial Dysfunction in Neurodegeneration](/mechanisms/mitochondrial-dysfunction)

Biomarker Pages

• [Tau PET in CBS/PSP](/biomarkers/tau-pet-cbs-psp)
• [MRI Atrophy Patterns in CBS/PSP](/biomarkers/mri-atrophy-cbs-psp)
• [DTI White Matter Changes in CBS/PSP](/biomarkers/dti-white-matter-cbs-psp)
• [Biomarkers for Progressive Supranuclear Palsy](/biomarkers/progressive-supranuclear-psp-biomarkers)
• [Biomarkers for Corticobasal Degeneration](/biomarkers/corticobasal-degeneration-biomarkers)

Treatment and Care Guides

• [CBS/PSP Treatment Rankings](/therapeutics/cbs-psp-treatment-rankings)
• [CBS/PSP Daily Action Plan](/therapeutics/cbs-psp-daily-action-plan)
• [CBS/PSP Rehabilitation Master Guide](/therapeutics/cbs-psp-rehabilitation-guide)
• [CBS/PSP Clinical Trials Guide](/therapeutics/cbs-psp-clinical-trials-guide)
• [Cognitive Reserve Strategies for CBS and PSP](/therapeutics/cognitive-reserve-cbs-psp)
• [Exercise and Physical Activity for CBS/PSP](/therapeutics/exercise-cbs-psp)
• [Progressive Supranuclear Palsy (PSP) Treatment](/therapeutics/progressive-supranuclear-psp-psp-treatment)
• [Corticobasal Degeneration (CBD) Treatment](/therapeutics/corticobasal-degeneration-treatment)

Intervention Monographs

• [Melatonin for Tauopathy: Comprehensive Evidence Synthesis](/therapeutics/melatonin-tauopathy)
• [Low-Dose Lithium for Tauopathy](/therapeutics/lithium-tauopathy)
• [Ambroxol for Neurodegeneration (GCase Chaperone Strategy)](/therapeutics/ambroxol-neurodegeneration)
• [Coenzyme Q10 for Neurodegeneration](/therapeutics/coenzyme-q10-neurodegeneration)
• [Omega-3 Fatty Acids (DHA/EPA) for Neurodegeneration](/therapeutics/omega-3-fatty-acids-neurodegeneration)
• [Alpha-Lipoic Acid for Neurodegeneration](/therapeutics/alpha-lipoic-acid-neurodegeneration)
• [NAD+ Precursors for Neurodegeneration](/therapeutics/nad-precursors-neurodegeneration)
• [Rapamycin for Tauopathy](/therapeutics/rapamycin-tauopathy)
• [Senolytic Therapies for CBS and PSP](/therapeutics/senolytics-neurodegeneration)
• [Spermidine and Autophagy Induction for Neurodegeneration](/therapeutics/spermidine-neurodegeneration)
• [TUDCA and UDCA Bile Acid Therapy for Neurodegeneration](/therapeutics/tudca-udca-neurodegeneration)
• [Photobiomodulation Therapy for Neurodegeneration](/therapeutics/photobiomodulation-neurodegeneration)
• [Curcumin for Neurodegeneration](/therapeutics/curcumin-neurodegeneration)
• [Vitamin D Therapy for Neurodegenerative Diseases](/therapeutics/vitamin-d-therapy-neurodegeneration)
• [Creatine for Neuroprotection](/therapeutics/creatine-neuroprotection)
• [Mediterranean and MIND Diets for Neurodegeneration](/therapeutics/mediterranean-mind-diet-neurodegeneration)

Cell-Type Vulnerability

• [Pedunculopontine Nucleus Cholinergic in Progressive Supranuclear Palsy](/cell-types/ppn-cholinergic-psp)
• [Locus Coeruleus Noradrenergic in Progressive Supranuclear Palsy](/cell-types/locus-coeruleus-psp)
• [Globus Pallidus Neurons in Corticobasal Degeneration](/cell-types/globus-pallidus-cbd)
• [Striatal Interneurons in Corticobasal Degeneration](/cell-types/striatal-interneurons-cbd)
• [Substantia Nigra Neurons in Progressive Supranuclear Palsy](/cell-types/substantia-nigra-neurons-progressive-supranuclear-palsy)
• [Substantia Nigra Neurons in Corticobasal Degeneration](/cell-types/substantia-nigra-neurons-corticobasal-degeneration)
• [Cortical Neurons in Corticobasal Degeneration](/cell-types/cortical-neurons-cbd)

Recent Research (2024-2026)

This section highlights recent publications relevant to this disease.

• [Eating Disorders and Parkinson's Disease - 2: Population Burden, Genetic Epidemiology and Shared Genomics.](https://pubmed.ncbi.nlm.nih.gov/41542687/) (2026 Jan 5) - medRxiv : the preprint server for health sciences
• [Pick Disease.](https://pubmed.ncbi.nlm.nih.gov/32965897/) (2026 Jan) -
• [SpikeID: Rapid and unbiased identification of SARS-CoV-2 variants by spike sequencing.](https://pubmed.ncbi.nlm.nih.gov/40774230/) (2025 Oct) - Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology
• [Genome-wide association study of REM sleep behavior disorder in Parkinson's disease.](https://pubmed.ncbi.nlm.nih.gov/40998812/) (2025 Sep 25) - NPJ [Parkinson's disease](/diseases/parkinsons-disease)
• [Acetylation Mimetic and Null Mutations Within the Filament Core of P301L Tau Have Varied Effects on Susceptibility to Seeding and Aggregation.](https://pubmed.ncbi.nlm.nih.gov/40917003/) (2025 Sep) - Journal of neurochemistry

References

[Unknown, Eating Disorders and Parkinson's Disease - 2: Population Burden, Genetic Epidemiology and Shared Genomics (n.d.)](https://pubmed.ncbi.nlm.nih.gov/41542687/)

[Unknown, Pick Disease (n.d.)](https://pubmed.ncbi.nlm.nih.gov/32965897/)

[Unknown, SpikeID: Rapid and unbiased identification of SARS-CoV-2 variants by spike sequencing (n.d.)](https://pubmed.ncbi.nlm.nih.gov/40774230/)

[Unknown, Genome-wide association study of REM sleep behavior disorder in Parkinson's disease (n.d.)](https://pubmed.ncbi.nlm.nih.gov/40998812/)

[Unknown, Acetylation Mimetic and Null Mutations Within the Filament Core of P301L Tau Have Varied Effects on Susceptibility to Seeding and Aggregation (n.d.)](https://pubmed.ncbi.nlm.nih.gov/40917003/)