How to Address Genetic Hearing Loss

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Decoding Silence: An In-Depth Guide to Addressing Genetic Hearing Loss

Hearing is a cornerstone of human experience, connecting us to the world through sound, language, and communication. For millions, however, this vital sense is impacted by hearing loss, and a significant portion of these cases have a genetic origin. Genetic hearing loss, often a silent inheritance, can present at birth or develop over time, affecting individuals across all age groups. Understanding its intricate nature, from the underlying genetic mutations to the diverse ways it manifests, is the first step toward effective management and fostering a life rich in communication and connection.

This comprehensive guide delves deep into the multifaceted aspects of addressing genetic hearing loss. We will explore the science behind it, unravel the various types and inheritance patterns, and provide a detailed roadmap of diagnostic pathways. Crucially, we will offer a thorough examination of current treatment modalities, from established amplification technologies to groundbreaking gene therapies. Beyond medical interventions, this guide will illuminate the crucial role of communication strategies, educational support, and the empowering impact of a strong support network. Our aim is to provide a definitive, actionable resource for individuals, families, and caregivers navigating the complexities of genetic hearing loss, ensuring every opportunity for a fulfilling life is seized.

The Genetic Blueprint of Sound: Understanding the Roots of Hearing Loss

At its core, genetic hearing loss stems from anomalies within an individual’s DNA, the very instructions that govern the development and function of our bodies, including the intricate auditory system. These genetic variations, or mutations, can disrupt any part of the hearing pathway, from the delicate structures of the inner ear to the neural pathways that transmit sound information to the brain.

The Role of Genes in Hearing

Our genes are like individual chapters in a vast instruction manual. Hundreds of genes are involved in the complex process of hearing. Some are responsible for forming the tiny hair cells in the cochlea, the inner ear’s spiral-shaped organ, which convert sound vibrations into electrical signals. Others dictate the development of the auditory nerve, while still more influence the balance of fluids and ions critical for proper inner ear function. A mutation in just one of these crucial genes can lead to a malfunction, resulting in hearing loss.

For example, the GJB2 gene is one of the most common culprits in non-syndromic genetic hearing loss, meaning hearing loss is the sole medical condition present. This gene provides instructions for making a protein called connexin 26, vital for the proper function of hair cells in the cochlea. A mutation in GJB2 can impair this protein’s function, leading to varying degrees of sensorineural hearing loss.

Syndromic vs. Non-Syndromic Genetic Hearing Loss

Genetic hearing loss is broadly categorized into two main types:

  • Non-Syndromic Hearing Loss: This is the more prevalent form, where hearing loss occurs in isolation, without any other associated medical conditions. As mentioned, mutations in the GJB2 gene are a prime example. An individual with non-syndromic hearing loss due to GJB2 mutation might have perfectly healthy vision, heart function, and kidney function, with hearing being the only affected sense.

  • Syndromic Hearing Loss: In these cases, hearing loss is one symptom among a constellation of other medical issues that form a recognized syndrome. There are over 400 known genetic syndromes that include hearing loss as a feature. A classic example is Usher syndrome, where individuals experience both hearing loss and progressive vision loss due to retinitis pigmentosa. Another is Jervell and Lange-Nielsen syndrome, characterized by profound sensorineural hearing loss and a heart condition that can cause life-threatening arrhythmias. Identifying these syndromes is critical as it guides comprehensive medical management for all associated conditions.

Patterns of Inheritance: How Hearing Loss Runs in Families

Understanding how genetic hearing loss is passed down through families is crucial for genetic counseling and family planning. The main inheritance patterns include:

  • Autosomal Recessive Inheritance: This is the most common pattern for non-syndromic genetic hearing loss. In this scenario, an individual must inherit two copies of the mutated gene (one from each parent) to develop hearing loss. If someone inherits only one mutated copy and one normal copy, they are typically a “carrier” and do not experience hearing loss themselves, but can pass the mutated gene to their children.
    • Concrete Example: Imagine two parents, neither of whom has hearing loss, but both carry one copy of a recessive GJB2 mutation. With each pregnancy, there is a 25% chance their child will inherit two copies of the mutated gene and have hearing loss, a 50% chance the child will be a carrier like them, and a 25% chance the child will inherit two normal copies and not be a carrier.
  • Autosomal Dominant Inheritance: In this pattern, only one copy of the mutated gene is needed for an individual to develop hearing loss. If a parent has a dominant form of genetic hearing loss, there is a 50% chance with each child that they will pass on the mutated gene and their child will also have hearing loss.
    • Concrete Example: A father has a dominant mutation causing progressive hearing loss that started in his 30s. Each of his children has a 50% chance of inheriting this mutation and potentially developing similar hearing loss later in life, regardless of whether their mother carries a related gene.
  • X-Linked Inheritance: This pattern involves genes located on the X chromosome. Since males have one X and one Y chromosome, and females have two X chromosomes, X-linked conditions often affect males more severely or frequently.
    • Concrete Example: A mother is a carrier for an X-linked gene mutation causing hearing loss. While she may not have hearing loss herself (due to having a second, functional X chromosome), each of her sons has a 50% chance of inheriting the mutated X chromosome and developing hearing loss. Each of her daughters has a 50% chance of being a carrier like her.
  • Mitochondrial Inheritance: Mitochondria are the “powerhouses” of our cells and contain their own small amount of DNA. Mitochondrial DNA is inherited exclusively from the mother.
    • Concrete Example: A mother has a mitochondrial mutation linked to hearing loss. All of her children, both sons and daughters, will inherit this mutation. However, the expression of mitochondrial conditions can vary, meaning not all children will necessarily develop the same degree of hearing loss or even any symptoms at all.
  • De Novo Mutations: Sometimes, a genetic mutation occurs spontaneously in an individual, meaning it was not inherited from either parent. This is referred to as a “de novo” mutation.
    • Concrete Example: A child is born with profound hearing loss, and genetic testing reveals a mutation in a specific gene. Further testing of both parents shows they do not carry this mutation, indicating it arose spontaneously in the child. While the child’s hearing loss is genetic, the likelihood of future siblings having the same condition may be very low unless germline mosaicism is present in a parent.

The Diagnostic Journey: Uncovering the Genetic Truth

A precise diagnosis of genetic hearing loss is paramount. It not only provides clarity for affected individuals and their families but also informs prognosis, potential associated health risks, and guides tailored intervention strategies. The diagnostic journey often involves a multidisciplinary approach.

Early Detection: Newborn Hearing Screening

The importance of early detection cannot be overstated, especially for congenital or early-onset hearing loss. Newborn hearing screening programs are now standard in many parts of the world. These simple, non-invasive tests (like Otoacoustic Emissions or Auditory Brainstem Response) are performed shortly after birth to identify potential hearing impairments.

  • Actionable Insight: If a newborn fails the initial screening, it is absolutely critical to follow up with a comprehensive audiological evaluation by an audiologist specializing in pediatrics as soon as possible, ideally by three months of age. Delays can significantly impact language and communication development.

Comprehensive Audiological Evaluation

Beyond initial screening, a complete audiological evaluation is essential to determine the type, degree, and configuration of hearing loss. This typically includes:

  • Behavioral Audiometry: For older children and adults, this involves responding to sounds at various pitches and loudness levels. For infants and young children, techniques like Visual Reinforcement Audiometry (VRA) or Conditioned Play Audiometry (CPA) are used, where a child’s head turn or play response is conditioned to sound.

  • Immittance Audiometry (Tympanometry): This test measures middle ear function, helping to differentiate between conductive (middle or outer ear issues) and sensorineural (inner ear or nerve issues) hearing loss.

  • Auditory Brainstem Response (ABR) and Auditory Steady-State Response (ASSR): These objective tests measure the brain’s response to sound, providing information about hearing thresholds, particularly useful for infants and those who cannot participate in behavioral tests.

Medical Evaluation by an Otolaryngologist (ENT)

An Ear, Nose, and Throat (ENT) specialist plays a crucial role in ruling out other causes of hearing loss (e.g., ear infections, structural abnormalities) and assessing the overall health of the ear. They may perform:

  • Physical Examination: To inspect the ear canal and eardrum.

  • Imaging Studies: Such as CT scans or MRI of the temporal bone, to visualize the inner ear structures and auditory nerve, especially if structural anomalies or other syndromic features are suspected. For example, an MRI might reveal cochlear malformations linked to specific genetic conditions.

Genetic Counseling and Testing: The Core of Diagnosis

Genetic counseling is a vital component of the diagnostic process for genetic hearing loss. A genetic counselor or clinical geneticist will:

  • Gather Family History: Constructing a detailed family pedigree to identify patterns of inheritance and affected relatives. This can provide crucial clues, such as multiple family members with early-onset hearing loss, suggesting an inherited cause.

  • Discuss Inheritance Patterns: Explain the different ways genetic hearing loss can be passed down and the implications for current and future family members.

  • Offer Genetic Testing: This involves analyzing an individual’s DNA to identify specific mutations linked to hearing loss.

    • Types of Genetic Tests:
      • Targeted Gene Panels: These panels test for mutations in a specific set of genes known to cause hearing loss (e.g., a panel for common non-syndromic hearing loss genes like GJB2 and GJB6).

      • Whole Exome Sequencing (WES): This more comprehensive test sequences all protein-coding regions of the genome, which can identify mutations in less common or newly discovered hearing loss genes.

      • Whole Genome Sequencing (WGS): The most exhaustive test, sequencing the entire genome, including non-coding regions, which may reveal regulatory mutations.

    • Concrete Example: A young child presents with profound bilateral sensorineural hearing loss. After initial audiological and medical evaluations, genetic testing using a comprehensive hearing loss gene panel is performed. The results reveal a pathogenic mutation in the OTOF gene, confirming a genetic etiology. This specific diagnosis allows for the family to understand the specific mechanism of their child’s hearing loss, and potentially explore emerging gene therapies targeting this specific gene.

  • Interpret Results: Explain the meaning of genetic test results, including the likelihood of recurrence in future children, the possibility of other health conditions (if syndromic), and potential implications for extended family members.

  • Provide Support and Resources: Connect families with support groups, educational resources, and other specialists.

Therapeutic Avenues: Addressing Genetic Hearing Loss

While the genetic mutation itself cannot currently be reversed (with the exception of groundbreaking gene therapies discussed later), the effects of genetic hearing loss can be effectively managed and treated through a range of interventions. The choice of intervention depends on the type, degree, and specific genetic cause of hearing loss, as well as individual needs and preferences.

1. Hearing Aids: Amplifying the World

Hearing aids are often the first line of intervention for mild to severe sensorineural hearing loss. They are sophisticated electronic devices designed to amplify sound and deliver it into the ear.

  • How They Work: A microphone picks up sound, a processor amplifies and modifies it based on the individual’s hearing loss profile, and a receiver (speaker) delivers the amplified sound into the ear canal. Modern digital hearing aids are highly customizable and can adapt to different listening environments.

  • Types:

    • Behind-the-Ear (BTE): The main unit sits behind the ear, with a tube connecting to an earmold in the ear canal. Suitable for all degrees of hearing loss, including profound.

    • Receiver-in-Canal (RIC) / Receiver-in-the-Ear (RITE): Similar to BTE, but the receiver is placed directly in the ear canal, making the device smaller and often more discreet.

    • In-the-Ear (ITE) / In-the-Canal (ITC) / Completely-in-Canal (CIC): Custom-molded to fit partially or entirely within the ear canal. Offer greater discretion but may not be suitable for severe-to-profound losses or individuals with very small ear canals.

  • Concrete Example: A child diagnosed with moderate sensorineural hearing loss due to a GJB2 mutation might be fitted with BTE hearing aids. The audiologist programs the aids to selectively amplify sounds at the specific frequencies where the child has the most hearing loss, ensuring that speech sounds are clearly audible without over-amplifying other sounds. Regular follow-up appointments are crucial to adjust the settings as the child grows and their auditory needs evolve.

2. Cochlear Implants: Bypassing Damaged Pathways

For individuals with severe to profound sensorineural hearing loss who receive limited or no benefit from traditional hearing aids, cochlear implants offer a transformative solution. Unlike hearing aids that amplify sound, cochlear implants bypass the damaged parts of the inner ear and directly stimulate the auditory nerve.

  • How They Work: A cochlear implant has two main parts:
    • External Processor: Worn behind the ear, it captures sound, converts it into digital signals, and transmits them to the internal implant.

    • Internal Implant: Surgically placed under the skin behind the ear, it receives signals from the external processor and sends electrical impulses to an electrode array inserted into the cochlea. These impulses stimulate the auditory nerve, which then sends sound information to the brain.

  • Candidacy: Candidacy for cochlear implantation is determined by a multidisciplinary team including an audiologist, ENT surgeon, speech-language pathologist, and often a psychologist. Factors considered include degree of hearing loss, lack of benefit from hearing aids, overall health, and commitment to rehabilitation.

  • Concrete Example: An infant with profound congenital hearing loss confirmed to be genetic (e.g., due to a mutation in the STRC gene) might undergo cochlear implantation as early as 9-12 months of age. Following surgery, intensive auditory verbal therapy and speech-language pathology are essential for the child to learn to interpret the electrical signals as sound and develop spoken language. The implant “opens up” access to sound, but the brain needs to learn to process this new input.

3. Other Assistive Listening Devices (ALDs)

Beyond hearing aids and cochlear implants, a variety of ALDs can further enhance communication and access to sound in specific situations.

  • FM Systems/Remote Microphones: These wirelessly transmit a speaker’s voice directly to a hearing aid or cochlear implant, reducing background noise and improving signal-to-noise ratio, particularly useful in classrooms or noisy environments.
    • Concrete Example: A student with genetic hearing loss using hearing aids in a noisy classroom can benefit immensely from an FM system. The teacher wears a small microphone, and their voice is transmitted directly to the student’s hearing aids, making it easier to hear instructions and participate in discussions over the general classroom chatter.
  • Loop Systems: Also known as induction loops, these transmit audio signals directly to hearing aids or cochlear implants equipped with a “telecoil” (T-coil) in public venues like theaters, places of worship, or lecture halls.

  • Alerting Devices: Flashing lights for doorbells or smoke detectors, vibrating alarm clocks, or amplified telephones help individuals with hearing loss stay aware of their surroundings and communicate effectively.

4. Emerging Therapies: The Horizon of Genetic Intervention

The field of genetic hearing loss is experiencing rapid advancements, with novel therapies moving from research labs to clinical trials. These emerging treatments aim to address the genetic defect at its source, offering the potential for more targeted and even curative interventions.

  • Gene Therapy: This groundbreaking approach aims to introduce a healthy copy of a gene into the cells of the inner ear to compensate for a mutated or missing gene.
    • Mechanism: Typically, a modified, non-disease-causing virus (called a viral vector) is used to deliver the functional gene to specific inner ear cells, such as the hair cells.

    • Current Progress: Significant progress has been made, particularly for mutations in the OTOF gene (otoferlin), which is crucial for the transmission of sound signals from hair cells to the auditory nerve. Clinical trials have shown promising results, with some individuals experiencing restoration of hearing.

    • Concrete Example: For a child diagnosed with profound hearing loss due to an OTOF gene mutation, they might be considered for participation in a clinical trial for OTOF gene therapy. This involves a one-time injection of a viral vector carrying a functional OTOF gene into the cochlea. The hope is that the delivered gene will enable the hair cells to produce functional otoferlin, thereby restoring the neural transmission of sound and allowing the child to hear.

  • Gene Editing (CRISPR/Cas9): This technology allows for precise modifications to an existing gene, either by correcting a mutation or “turning off” a faulty gene.

    • Mechanism: CRISPR acts like molecular scissors, cutting DNA at specific locations, enabling the removal or insertion of genetic material.

    • Current Progress: While still largely in preclinical stages for hearing loss, gene editing holds immense potential for directly repairing genetic defects, offering a more permanent solution than gene replacement.

  • Cell Regeneration: Research is ongoing into methods to regenerate damaged hair cells in the cochlea, which are critical for hearing but do not naturally regenerate in mammals. This involves using stem cells or activating dormant cellular pathways.

  • Small Molecule Drugs: For certain genetic hearing losses, small molecule drugs might be developed to target specific biochemical pathways affected by the genetic mutation. These drugs could potentially protect existing hair cells or improve their function.

  • Crucial Note: It’s vital to emphasize that most of these emerging therapies are still in experimental phases. Families should consult with their healthcare providers and genetic specialists for the latest information and to determine eligibility for clinical trials.

Holistic Management: Beyond the Medical Horizon

Addressing genetic hearing loss extends far beyond medical interventions. A holistic approach encompasses communication strategies, educational support, psychosocial well-being, and a strong network of support.

1. Communication Strategies: Bridging the Sound Gap

Effective communication is paramount for individuals with hearing loss. A range of strategies can be employed, tailored to the individual’s hearing abilities, preferences, and cultural background.

  • Auditory-Verbal Therapy (AVT): This therapy focuses on developing listening and spoken language skills in children with hearing loss, particularly those with hearing aids or cochlear implants. It emphasizes the importance of early intervention and consistent auditory input.
    • Concrete Example: A toddler with a cochlear implant attends regular AVT sessions where a therapist guides parents on how to create a rich auditory environment, encourage listening, and model spoken language through everyday interactions like reading books, singing songs, and describing actions.
  • Sign Language: For many individuals, particularly those with profound hearing loss or those who prefer a visual-manual language, sign language (such as American Sign Language – ASL, or British Sign Language – BSL) provides a complete and robust means of communication.
    • Concrete Example: A family with a child diagnosed with profound genetic hearing loss may choose to learn sign language as their primary mode of communication. This allows for immediate and natural communication within the family and connects them to the vibrant Deaf community.
  • Cued Speech: A visual system that uses handshapes and positions near the mouth to clarify the sounds of spoken language, making lip-reading more accurate.

  • Total Communication: An approach that integrates various communication modes, including spoken language, sign language, gestures, and visual aids, allowing the individual to use whatever method is most effective at any given moment.

  • Lip-reading (Speechreading): The ability to understand spoken language by observing the movements of a speaker’s lips, face, and tongue. While helpful, it’s rarely a complete communication solution on its own.

  • Communication Partner Strategies: Educating family members, friends, and colleagues on effective communication techniques, such as speaking clearly and at a moderate pace, facing the person, reducing background noise, and rephrasing if necessary.

2. Educational Support: Nurturing Learning and Development

Children with genetic hearing loss require tailored educational support to thrive academically and socially.

  • Individualized Education Programs (IEPs) / 504 Plans: These legally binding documents outline the specific educational services and accommodations a student with hearing loss will receive in school.
    • Concrete Example: An IEP for a child with moderate genetic hearing loss might include preferential seating in the classroom, use of an FM system, access to a note-taker or captioning services for lectures, and regular support from a Teacher of the Deaf/Hard of Hearing.
  • Early Intervention Programs: For infants and toddlers, these programs provide a foundation for language, cognitive, and social development. They often involve a team of professionals, including audiologists, speech-language pathologists, and special educators.

  • Specialized Schools/Programs: Some children may benefit from schools or programs specifically designed for students who are deaf or hard of hearing, offering a supportive environment with peers and specialized instructors.

  • Inclusion with Support: Many children thrive in mainstream schools with appropriate accommodations and support services.

  • Technology in Education: Utilizing tools like captioning for videos, interactive whiteboards, and speech-to-text software can significantly enhance learning for students with hearing loss.

3. Psychosocial Well-being: Addressing the Emotional Landscape

Living with hearing loss, especially a genetic form, can have significant psychosocial impacts on individuals and families. Addressing these emotional and social aspects is crucial for overall well-being.

  • Emotional Support and Counseling: Individuals may experience feelings of isolation, frustration, anxiety, or depression. Counseling, either individually or as a family, can provide strategies for coping, communication, and self-advocacy.

  • Peer Support Groups: Connecting with others who share similar experiences can be incredibly empowering, fostering a sense of community and reducing feelings of isolation.

    • Concrete Example: Parents of a newly diagnosed infant with genetic hearing loss might join a local support group for families of children with hearing loss. Sharing experiences, challenges, and successes with other parents can provide invaluable emotional support and practical advice.
  • Advocacy and Self-Advocacy: Learning to advocate for one’s needs, whether it’s requesting accommodations at work or school, or educating others about hearing loss, is a critical skill. Organizations dedicated to hearing loss can provide resources and guidance on advocacy.

  • Building Self-Esteem and Identity: Encouraging a positive self-identity, embracing one’s hearing status, and celebrating the unique perspectives that come with it can foster resilience and confidence.

4. Family Support and Genetic Counseling (Ongoing)

Genetic counseling is not a one-time event; it can be an ongoing resource for families as new questions arise or circumstances change.

  • Recurrence Risk Discussions: For families planning future pregnancies, genetic counselors can provide updated information on recurrence risks based on the specific genetic diagnosis.

  • Carrier Testing for Family Members: Other family members, especially siblings of an affected individual, may choose to undergo genetic testing to determine if they are carriers of a specific mutation, which can inform their own family planning decisions.

  • Navigating Syndromic Manifestations: For syndromic hearing loss, genetic counselors work closely with other specialists to monitor and manage the full spectrum of associated conditions, ensuring a comprehensive approach to care.

    • Concrete Example: A family with Usher syndrome will have ongoing genetic counseling to understand the progressive nature of both hearing and vision loss, and to connect with specialists for regular ophthalmological evaluations and potential interventions like low-vision aids or gene therapy trials for retinal degeneration.
  • Emotional Processing: Genetic counselors offer a safe space for families to process the emotional impact of a genetic diagnosis, from initial shock and grief to acceptance and empowerment.

Living a Fulfilling Life: Strategies for Success

Beyond the direct interventions, certain strategies and mindsets contribute significantly to a fulfilling life with genetic hearing loss.

Proactive Health Management

  • Regular Audiological Check-ups: Consistent monitoring of hearing levels and device performance is crucial, especially for progressive hearing loss. This ensures hearing aids or cochlear implants are optimally programmed and adjusted.

  • Protecting Residual Hearing: Avoiding excessive noise exposure and ototoxic medications (drugs that can damage hearing) is essential to preserve any remaining hearing.

  • General Health and Well-being: Maintaining a healthy lifestyle, including a balanced diet and regular exercise, contributes to overall health, which can positively impact hearing health.

Embracing Technology and Innovation

  • Staying Informed: The field of hearing science and genetics is constantly evolving. Staying abreast of new research, technologies, and clinical trials is important. Reliable sources of information often include university medical centers, research institutions, and reputable patient advocacy organizations.

  • Leveraging Smart Devices: Many modern hearing aids and cochlear implants offer Bluetooth connectivity to smartphones, allowing for direct streaming of phone calls, music, and other audio, significantly enhancing daily communication and entertainment. Apps can also provide additional control and customization.

    • Concrete Example: An individual with genetic hearing loss using a compatible hearing aid can stream a video conference call directly to their devices, bypassing problematic room acoustics and making the conversation clearer and more manageable.

Building a Robust Support Network

  • Family and Friends: Educating loved ones about hearing loss and how best to communicate can significantly reduce communication breakdowns and foster a more inclusive environment.

  • Healthcare Professionals: Maintaining strong relationships with audiologists, ENTs, geneticists, speech-language pathologists, and other specialists ensures comprehensive and coordinated care.

  • Community and Advocacy Groups: Engaging with local or national organizations dedicated to hearing loss provides a wealth of resources, opportunities for connection, and a platform for advocacy. These groups often host events, workshops, and provide information on financial assistance for devices or therapies.

  • Online Communities: Virtual platforms offer accessible ways to connect with others facing similar challenges, share experiences, and seek advice.

Fostering Resilience and Adaptability

  • Problem-Solving Approach: Viewing challenges related to hearing loss as problems to be solved rather than insurmountable obstacles. This might involve experimenting with different communication strategies, assistive devices, or environmental modifications.

  • Positive Mindset: While acknowledging the difficulties, cultivating a positive outlook and focusing on strengths and opportunities for growth.

  • Self-Compassion: Recognizing that living with hearing loss can be demanding and practicing self-care and understanding.

Conclusion

Genetic hearing loss, while often presenting unique challenges, is a condition that can be effectively addressed, allowing individuals to lead rich, fulfilling lives. From the precision of genetic diagnosis to the transformative power of modern hearing technologies and the promise of emerging therapies, the landscape of care is continuously advancing. However, true empowerment comes not just from medical interventions, but from a comprehensive approach that prioritizes clear communication, robust educational support, emotional well-being, and strong community connections.

By understanding the genetic underpinnings, pursuing accurate diagnoses, proactively engaging with available treatments, and embracing a holistic strategy that leverages technology and fosters resilience, individuals and families can navigate the complexities of genetic hearing loss with confidence. The journey may involve adaptations and learning, but with the right knowledge, resources, and support, the world of sound and connection remains within reach, ensuring that a life lived with genetic hearing loss is one of inclusion, opportunity, and profound personal growth.