Epigenetic Markers and Transgenerational Effects in Misophonia

Technical abstract

Misophonia, characterized by strong negative emotional responses to specific auditory stimuli, remains poorly understood, particularly its biological underpinnings. This research project focuses on elucidating the epigenetic factors contributing to this condition. We postulate that epigenetic modifications such as DNA methylation patterns and histone tail acetylation states significantly contribute to both the expression and possible intergenerational transmission of misophonia predispositions.

In order to investigate this hypothesis, our multidisciplinary approach will employ state-of-the-art next-generation sequencing technologies complemented by robust bioinformatics analyses. This will allow for a comprehensive comparison of the epigenetic landscapes across three distinct groups: individuals clinically diagnosed with misophonia, their unaffected family members, and a cohort of control individuals with no familial incidence of the condition. By examining these profiles, we aim to identify specific epigenetic signatures that are consistently associated with misophonic traits.

A critical aspect of this study is its innovative multi-generational family-based design, which will be pivotal in assessing the potential for epigenetic changes to be inherited across generations. This segment of the study will provide insights into the role environmental and experiential factors play, particularly those which might influence stress response pathways analogous to PTSD mechanisms, given their neural and psychological parallels.

We will also incorporate detailed psychometric assessments designed to quantify stress responses and related symptom clusters within the framework of misophonia, thereby providing a holistic view of how these epigenetic modifications may manifest behaviorally and physiologically.

The expected outcomes of this research are to identify reliable epigenetic biomarkers that not only enhance the understanding of misophonia at a molecular level but also pave the way for early diagnostic tools. Further, these biomarkers may inform the development of personalized interventions, improving therapeutic approaches for individuals affected by misophonia. By extending our findings to include hereditary patterns, we might also highlight novel pathways for preventing transmission and emergence of related reactive conditions. This work stands to contribute significantly to the fields of neurogenetics and auditory neurobiology, offering potential breakthroughs in managing sensory processing disorders.

Impact statement

The societal impact of this research is profound. By unveiling the epigenetic mechanisms underlying misophonia, potentially identifying biomarkers that are both diagnostic and therapeutic in nature, we open new avenues for early intervention, potentially alleviating the significant distress faced by individuals with this condition. Early diagnosis, enabled by such biomarkers, would provide individuals and families with knowledge and tools to better manage symptoms, reducing the overall psychological burden and enhancing social integration and occupational productivity.

From an academic perspective, the findings of our study are poised to propel forward the fields of neurogenetics and auditory neurobiology, particularly in understanding sensory processing disorders. By establishing a link between specific epigenetic modifications and misophonic traits, we advance the current paradigms regarding the interplay of heredity and environment in neuropsychiatric disorders. This has the potential to shift the existing scholastic dialogue surrounding hereditary traits and psychiatric conditions by emphasizing epigenetic rather than solely genetic contributions.

Moreover, our work will serve as a pioneering study for subsequent research into the intergenerational transmission of epigenetic changes, an area ripe for exploration given contemporary shifts towards recognizing the impact of non-genetic inheritance. The methodological innovations, including the use of cutting-edge sequencing technologies and multi-generational analysis, will provide a robust framework for future studies aiming to investigate similar conditions. Ultimately, this research could lead to paradigm shifts both in the theoretical understanding and practical management of sensory processing and related disorders, laying the groundwork for a more nuanced approach to cognitive and behavioral health research and care.

Literature review

Recent literature highlights substantial advancements in understanding misophonia, a condition that elicits strong emotional and physiological reactions to specific sounds, such as chewing or tapping. Trumbull et al. (2024) emphasized the inadequacies in subjective measurement approaches, proposing a standardized sound set, the International Affective Digital Sounds-2 (IADS-2), to objectively measure misophonia responses. Their research provided critical insights into how individuals with misophonia experience typically neutral sounds as aversive, underscoring the need for contextually relevant diagnostic tools and therapeutic interventions.

Several studies, including Guetta et al. (2024), explored the relationship between stress and misophonia, elucidating how perceived stress, but not traumatic stress, correlates with the severity of misophonia. This suggests that addressing non-trauma-specific stress factors should be integral to treatment plans, diverging from traditional trauma-focused approaches, which may not address the core elements of the condition.

In the domain of treatment, Köroğlu and Durat (2024) offered an overview of therapeutic strategies, highlighting the absence of standardized protocols despite promising results from therapies such as CBCT, ACT, and EMDR. They called for empirical validation of these treatments across broader clinical settings, considering the disorder's complexity and its significant impact on quality of life. This was further illustrated by Jager et al. (2021), whose pilot study on EMDR therapy indicated moderate improvements in emotional and behavioral symptoms of misophonia, emphasizing the necessity for treatments addressing emotional dysregulation.

Barahmand et al. (2023) added depth to the understanding of misophonia by investigating the connection between different types of disgust—such as sexual and pathogen—and misophonia, mediated by mental contamination. This nuanced perspective suggests that misophonia diverges from traditional psychiatric conditions like OCD and could benefit from alternative therapeutic approaches.

Identification of Gaps

Despite these contributions, current research has several limitations. Firstly, there is a lack of exploration into the biological underpinnings of misophonia, including potential genetic and epigenetic contributions. The presence of stress-related symptomatology in misophonia suggests possible epigenetic modifications, akin to those found in stress-related disorders. However, no studies have examined the role of DNA methylation and histone acetylation in misophonia comprehensively, especially across family generations.

Furthermore, while current research underscores the need for standardized diagnostic and therapeutic protocols, the transgenerational transmission of such epigenetic changes remains uninvestigated. This gap inhibits the understanding of heritable aspects of misophonia and potential interventional strategies targeting these mechanisms.

Purpose of the Current Study

Addressing these gaps, the present study aims to investigate the epigenetic basis of misophonia within family systems. It will explore DNA methylation and histone acetylation across generations, providing insights into heritable epigenetic modifications relevant to stress and auditory processing disorders. By leveraging advanced sequencing technologies, this research seeks to expand the psychosocial context by incorporating an in-depth examination of stress-related symptomatology.

This study not only aims to elucidate the biological mechanisms underlying misophonia but also intends to pave the way for developing more effective diagnostic tools and individualized treatment interventions. These findings could significantly impact how misophonia is understood and managed, ultimately contributing to improved quality of life for those affected by this condition.

Aims

• Identify Specific Epigenetic Markers Associated with Misophonia

  • Utilize next-generation sequencing technologies to map the comprehensive epigenetic profiles of individuals diagnosed with misophonia, unaffected family members, and control individuals without familial incidence of the condition.
  • Analyze DNA methylation and histone modification patterns to delineate distinct epigenetic signatures that consistently correlate with misophonic traits.
  • Facilitate bioinformatics analysis to isolate candidate genes and pathways involved in misophonia, providing foundational data for potential diagnostic marker development.

• Evaluate the Potential for Transgenerational Epigenetic Inheritance of Misophonia

  • Employ a multi-generational family-based study design to observe the potential transmission of epigenetic modifications from parents diagnosed with misophonia to their offspring.
  • Investigate the consistency of specific epigenetic markers across generations to assess heritability and the potential impact of parental factors on progeny's epigenetic landscape.
  • Contribute to understanding how non-genetic factors may influence the inheritance of sensory processing disorders, thereby informing novel pathways for intervention and prevention.

• Assess the Influence of Environmental Stress and PTSD Symptoms on Epigenetic Changes in Individuals with Misophonia

  • Integrate psychometric assessments to evaluate the relationship between environmental stressors, PTSD-like symptomatology, and epigenetic modifications in misophonic patients.
  • Correlate levels of stress and emotional responses with changes in key epigenetic markers to determine how such factors may exacerbate or mitigate misophonia symptoms.
  • Enhance understanding of the neurobiological intersections between stress responses and auditory processing disorders, guiding personalized treatment approaches targeting these pathways.

Scientific approach

To achieve the aims outlined in this proposal, our research will involve a methodologically robust and multidisciplinary approach tailored to unravel the complex interplay of epigenetics in misophonia. The scientific approach can be outlined in three interconnected phases: sample recruitment and preparation, data acquisition through advanced sequencing technologies, and the integration of advanced analytical techniques to evaluate epigenetic modifications and their potential heritability.

Phase 1: Sample Recruitment and Characterization

The first step in our research involves the careful selection and recruitment of participants categorized into three distinct groups: individuals clinically diagnosed with misophonia (Group A), their unaffected family members (Group B), and matched control individuals without any familial history of the condition (Group C). We will recruit participants from diverse backgrounds, ensuring a sufficient sample size to achieve statistical power necessary to detect significant epigenetic differences.

Each participant will undergo comprehensive clinical assessments to ensure accurate diagnosis and classification using validated criteria for misophonia and related disorders. Additionally, participants in Groups A and B will complete psychometric assessments, including standardized stress and PTSD questionnaires, to capture individual stress profiles and environmental factors possibly influencing epigenetic changes.

Phase 2: Epigenetic Profiling

Using non-invasive biological sampling methods (blood or saliva samples), we will extract high-quality genomic DNA from all participants. The DNA samples will then undergo bisulfite conversion for methylation-specific analysis and chromatin immunoprecipitation (ChIP) for histone modification assessment. This will prepare the samples for detailed analysis using next-generation sequencing technologies, specifically whole-genome bisulfite sequencing (WGBS) and ChIP-seq.

These cutting-edge methodologies will facilitate the comprehensive mapping of the methylome and histone modification landscape, respectively, across our cohorts. To ensure data validity and reliability, we will implement stringent quality control measures at every stage, from sample collection through sequencing, following established laboratory and computational protocols.

Phase 3: Bioinformatics and Statistical Analysis

Upon obtaining sequencing data, comprehensive bioinformatics analysis will be performed to identify differentially methylated regions (DMRs) and histone modifications characteristic of misophonia. We will use sophisticated software platforms and pipelines, such as the Galaxy Project and R/Bioconductor packages, for processing and analyzing sequencing data. Initial analysis will focus on identifying epigenetic markers that correlate with misophonia severity and symptomatology, leveraging machine learning algorithms to uncover complex patterns within the data.

Concurrently, we will evaluate the potential heritability of these markers by conducting family-based association studies (FBAS) to compare epigenetic profiles between parents and offspring within affected families. This will be supplemented with longitudinal analysis of existing family health records to assess consistency and persistence of these epigenetic changes across generations.

Integration and Correlation with Phenotypic Data

Finally, to connect epigenetic findings with clinical and environmental data, we will perform cross-sectional analyses correlating identified epigenetic patterns with psychometric data related to stress and PTSD. Regression models and multivariate analyses will be employed to decipher how specific environmental and psychological factors might modulate epigenetic modifications linked to misophonia.

By integrating genetic, clinical, and environmental data, this research aims to map a holistic picture of how epigenetic alterations contribute to misophonia and its heritability. This approach not only promises to enrich our understanding of the biological foundation of misophonia but also sets a precedent for studying epigenetic transmission of complex traits in neuropsychiatric disorders.

Recruitment

Target Population

The target population for this study includes three distinct categories:

1. Individuals Clinically Diagnosed with Misophonia: These are individuals who have received a formal diagnosis of misophonia from a qualified healthcare professional and exhibit typical symptoms associated with the condition.
2. Immediate Family Members of Diagnosed Individuals: This group comprises parents and children (spanning at least two generations) of individuals diagnosed with misophonia, who do not display symptoms themselves. This familial recruitment is essential for investigating potential transgenerational epigenetic markers.
3. Unaffected Control Group: These are individuals without any personal or familial history of misophonia, serving as a baseline comparison to better understand the epigenetic differences.

Recruitment Plan

Recruitment will be strategically executed through multiple channels to ensure a representative and comprehensive sample size:

• Clinical Referrals: We will collaborate with clinics and healthcare providers specializing in sensory processing disorders and auditory sensitivities to identify and refer potential participants who meet the diagnostic criteria for misophonia.
• Online Platforms and Support Groups: Participation avenues will be opened through digital forums and communities dedicated to misophonia, leveraging online outreach for national and international recruitment.
• Genetic Studies Databases: We will utilize existing genetic research databases, which often involve individuals interested in participating in further research due to their complex traits and family history.

Inclusion Criteria

To participate in this study, individuals must meet the following criteria:

• For those with misophonia: A verified clinical diagnosis of misophonia using standardized assessment tools and criteria.
• For family members: Willingness to participate and criteria matching for family member roles (parent or child) linked to participants with misophonia.
• For controls: No personal or familial history of misophonia to ensure a true control environment for the study.
• Age range between 10 and 65 years to capture a wide developmental and generational span while maintaining relevance to transgenerational inheritance patterns.

Exclusion Criteria

Individuals will be excluded based on the following conditions:

• Presence of severe psychiatric disorders such as schizophrenia or bipolar disorder, which may confound the study’s focus on misophonia-specific stress responses and epigenetic marks.
• The existence of hearing impairments unrelated to misophonia, such as age-related hearing loss or ototoxicity, which could impact auditory response assessments.
• Inability or unwillingness to provide informed consent or, in the case of minors, lack of guardian consent for participation.

Accompanying Assessments

Participants diagnosed with misophonia and their family members will undergo a series of diagnostic assessments to quantify misophonic responses and evaluate associated stress or PTSD conditions:

• Misophonia Assessment Questionnaire (MAQ): A structured tool utilized to quantify misophonia severity and specific trigger responses.
• Perceived Stress Scale (PSS) and PTSD Checklist (PCL-5): To measure stress levels and PTSD-like symptoms, providing necessary psychometric background for correlating stress responses with epigenetic markers.

These assessments will not only ensure that participants meet all diagnostic criteria but will also provide important data for subsequent analysis of the interplay between environmental stresses and identified epigenetic changes.

Analytic methods

The analysis of the epigenetic data, derived from high-throughput sequencing, will be carried out using a comprehensive suite of bioinformatics and statistical tools designed to identify differential epigenetic markers and assess their implications for misophonia across samples.

Data Preprocessing

• Quality Control: Initial quality checks will involve using FastQC for read quality assessment to ensure raw data integrity. Trimming and filtering of low-quality reads will be conducted with tools such as Trimmomatic.
• Alignment and Mapping: Processed reads will be aligned to the reference human genome (GRCh38) using Bismark, specifically for the methylation data, and Bowtie2 for ChIP-seq data.

Epigenetic Analysis

• Methylation Analysis: For identifying differentially methylated regions (DMRs), we will employ tools like methylKit and DSS within the R environment. These tools allow for the statistical comparison of methylation levels among individuals with misophonia, their family members, and controls.
• Histone Modification Analysis: ChIP-seq data will be analyzed using MACS2 for peak calling to identify significant histone modification sites. Heatmaps and clustering analyses will be carried out using tools such as deepTools to visualize and interpret histone landscape alterations.

Statistical Approach

• Mixed-effects Models: To account for the repeated measures and nested structure of family data (e.g., multiple generations), we will implement linear mixed-effects models (LMMs) using the lme4 package in R. This will help in understanding how epigenetic variations are influenced by factors such as genetic background, familial relationships, and environmental stressors.
• Family-Based Association Studies (FBAS): Employing tools like FBAT, we will explore the intergenerational transmission of epigenetic markers, assessing the statistical association of identified DMRs and histone modifications within family cohorts.

Correlational and Regression Analyses

• Phenotype-Epigenotype Correlations: To discern potential links between stress-related phenotypes and epigenetic markers, we will conduct Pearson and Spearman correlation analyses on standardized psychometric scores (from PSS and PCL-5) and identified epigenetic changes.
• Multivariate Regression Models: We will refine our analysis using multivariate regression techniques to control for confounding variables, allowing for a clear interpretation of the impact of environmental stressors on epigenetic modifications.

Machine Learning Techniques

• Pattern Recognition and Prediction: Advanced machine learning methods, including unsupervised clustering (e.g., hierarchical clustering and t-SNE) and supervised learning (e.g., random forests), will be utilized to identify distinct epigenetic patterns predictive of misophonia presence and severity. These techniques will enhance our ability to categorize individuals based on their epigenomic signatures.

These integrative analytic methods collectively aim to capture and elucidate the complex relationships between epigenetic modifications and the psychosocial features of misophonia, enhancing our understanding of its biological basis and hereditary patterns.

Timeline

Year 1: Finalize Study Design and Obtain Ethical Approvals

• Q1-Q2:
  • Refine and finalize study design, ensuring all methodological aspects align with the project objectives.
  • Develop detailed protocols for participant recruitment, sample collection, and data analysis.
  • Establish collaborations and secure target participant recruitment sites, including clinical and community-based sources.
• Q3-Q4:
  • Prepare and submit applications for ethical approval to institutional review boards (IRBs) or ethics committees.
  • Develop informed consent forms and participant information sheets, including privacy and data handling protocols.
  • Conduct initial training sessions for research staff on protocols and ethical standards.

Year 1-2: Conduct Recruitment and Initial Data Collection

• Q1-Q2 (Year 1):
  • Launch recruitment strategies through clinics, support groups, and online platforms.
  • Organize informational sessions and outreach events to raise awareness and attract eligible participants.
• Q3-Q4 (Year 1):
  • Begin enrolment of participants in the three targeted groups: misophonia patients, unaffected family members, and control subjects.
  • Conduct preliminary psychometric assessments to gather baseline data on recruited participants.
• Q1-Q2 (Year 2):
  • Continue participant recruitment and complete baseline psychometric evaluations.
  • Begin collection of biological samples (blood or saliva) for initial epigenetic analyses.

Year 2-3: Perform Next-Generation Sequencing and Data Preprocessing

• Q3-Q4 (Year 2):
  • Commence extraction of high-quality genomic DNA from collected samples.
  • Conduct bisulfite conversion and chromatin immunoprecipitation (ChIP) for subsequent sequencing.
• Q1-Q2 (Year 3):
  • Establish protocols for quality control and data processing specific to sequencing outputs.
  • Initiate whole-genome bisulfite sequencing (WGBS) and ChIP-seq to identify epigenetic markers.
  • Begin preprocessing sequencing data including read alignment and quality filtering.

Year 3-4: Analyze Epigenetic Data and Psychometric Outcomes

• Q3-Q4 (Year 3):
  • Conduct bioinformatics analysis to identify differentially methylated regions (DMRs) and significant histone modifications.
  • Perform statistical analysis to correlate epigenetic signatures with baseline psychometric data.
• Q1-Q2 (Year 4):
  • Integrate machine learning techniques to refine identification of epigenetic patterns associated with misophonia traits.
  • Conduct comprehensive family-based association studies to explore heritability and intergenerational transmission of epigenetic markers.

Year 4: Integrate Findings and Prepare Manuscripts for Publication

• Q3 (Year 4):
  • Synthesize findings from bioinformatics and statistical analyses.
  • Assess the broader implications of epigenetic markers in relation to misophonia pathology and heritability.
• Q4 (Year 4):
  • Draft and submit findings to peer-reviewed journals, focusing on the biological underpinnings and potential interventions for misophonia.
  • Share results with the scientific community through conferences and symposiums.
  • Prepare a final report summarizing project outcomes, contributions to the field, and future research directions.

Conclusion

In conclusion, this research project anticipates significant advancements in understanding the biological underpinnings of misophonia through the identification of specific epigenetic markers. By employing next-generation sequencing technologies and a comprehensive family-based design, our study is poised to uncover distinct methylation and histone modification patterns associated with misophonia. The anticipated findings are expected to provide a deeper understanding of the potential hereditary nature of the condition, which might elucidate how these epigenetic changes could be influenced by environmental stressors.

Our work will contribute valuable insights into the neurogenetic and epigenetic landscapes of sensory processing disorders, with both immediate and long-term implications. In the short term, the identification of reliable epigenetic biomarkers can enhance diagnostic precision, leading to earlier recognition and management of misophonia, thus improving the quality of life for affected individuals. In the long term, this research may open avenues for tailored interventions designed to target these epigenetic markers, potentially mitigating misophonic symptoms and preventing their intergenerational transmission.

Future research should build upon these findings by investigating therapeutic interventions aimed at modifying identified epigenetic markers and exploring their applicability not only in misophonia but also across a spectrum of sensory processing disorders. Additionally, longitudinal studies would be valuable to observe the dynamic nature of these epigenetic changes over time and how they influence disease progression or response to treatment.

By advancing our understanding of the epigenetic contributions to misophonia, this study sets a strong foundation for future research, thereby fostering potential breakthroughs in personalized medicine approaches for sensory disorders, and influencing broader discussions on the genetics of auditory processing conditions.