Hereditary Hearing Loss – Genetics & Hearing Loss

Genetics and Hearing Loss

Hereditary Hearing Loss: A genetic counsellor and a specialist who specialises in paediatric genetics will examine your child. Your child's medical and family history will be gathered, and the doctor will perform a physical examination. This assessment can reveal which genes are most likely to be implicated in your child's hearing loss and which genetic testing choices are most appropriate. The genetics team will also provide information on how hearing loss can be passed down through generations and support services and recommendations to additional specialists as needed.
As we get older, we get age-related hearing loss (presbycusis). Regular treatment for health disorders like high blood pressure or diabetes is harmful to the ear's sensory hair cells. About half of all childhood deafness is caused by hereditary factors. Hereditary hearing loss can take several forms, including Usher syndrome or Pendred syndrome, age-related hearing loss, and otosclerosis.

A family audiogram, ocular examination, imaging of the inner ear, urine examination for microscopic haematuria, testing for congenital CMV, and discussion of genetic referral are all routine initial investigations for most types of sensorineural hearing loss.

Hearing loss due to ear, nose, and throat problems at home It's all too easy to take our ability to hear for granted. On the other hand, hearing loss is on the rise and is now the third most frequent health problem in the United States. Hearing loss can be caused by so many things, including age, disease, heredity, and drugs and exposure to loud, continuous noise. Hearing care specialists at Nebraska Medicine will figure out what's wrong and, if feasible, help you regain some hearing or treat permanent hearing loss with hearing aids or other devices.

Is your child's hearing loss genetic?

When a kid is born with hearing loss or develops a hearing loss in early childhood, the reason is genetic and attributable to a genetic change or mutation in more than half of the instances. The majority of children with hereditary hearing loss have no additional birth abnormalities or significant health issues.

On the other hand, some types of hereditary hearing loss may be linked to a hereditary syndrome that includes other health issues such as heart defects, eyesight problems, or developmental delays.

Sensorineural hearing loss (NHL), amelogenesis imperfecta, nail abnormalities, and, in some instances, retinal pigmentation are all symptoms of Heimler syndrome (hs; mim# 234580). The cause of hs is unknown genetically. In this paper, I describe the results of a research of eighths families.

In six families, whole-exome sequencing, SNP arrays, and Sanger sequencing revealed biallelic mutations in pex1 or pex6. A spectrum of autosomal recessive peroxisome biogenesis disorders (pbds), including Zellweger syndrome, is known to be caused by loss-of-function mutations in pex1 and pex6. Hypomorphic mutations, or the combination of a loss of function and a hypomorphic mutation, cause hs, as I show here.

Hereditary hearing loss (hhl) is a neurosensory condition that affects one in every 500 infants and approximately one-third of persons over 65 around the world. Congenital deafness is a hereditary condition that can be monogenetic or polygenic.

The intricacy, heterogeneity, and deep position of the inner ear below the brainstem and the small number of cells present in the cochlea are critical obstacles for current therapeutic efforts to cure deafness. Targeted genome editing is a promising treatment option for hhl because it can restore normal cochlear function by targeting faulty molecular components of the auditory transmission.

The key to a successful history is to seek hearing loss risk factors, inquire about balance (since this might be compromised without being part of the initial complaint), and uncover genetic risks in three-generation family history.

Document the impact of hearing loss on developmental abilities, speech, language, and communication if hearing loss is not detected at the newborn hearing screening and the child is older. Since 2015, the British Society of Audiology has suggested that when a child is old enough, they be inquired about tinnitus.

Children with Hearing Loss Can Hear and Talk

Hearing is a complicated process, so it's no wonder that the reasons for hearing loss are complicated as well. Damage to the ear, particularly the inner ear, can cause hearing loss. Babies may be born with hearing loss due to a viral infection contracted during pregnancy, for example.

In some instances, the cause is hereditary, resulting from mutations in genes linked to the hearing process. Hearing loss can sometimes be caused by a mix of hereditary and environmental causes. For example, some people are more likely to experience hearing loss after using specific antibiotics due to a genetic mutation.

Over the last 25 years, the relative incidence of different types of sensorineural hearing loss in children has altered dramatically.

Rubella in the mother, postnatal ototoxicity

Maternal rubella infection, postnatal ototoxicity, and meningitis were once the leading causes of severe and profound sensorineural hearing loss, but, thanks to a vaccine, maternal rubella infection as a cause of congenital hearing loss has almost totally disappeared.

As a cause of congenital deafness, it has nearly completely disappeared. Similarly, widespread vaccination against Haemophilus influenzae type b has lowered the prevalence of meningitis-related deafness in children.

Despite your hearing loss, these methods can help you communicate more effectively:
You can share this message with your friends and family. Inform them that you suffer from hearing loss.

Place yourself in a listening position. Look the individual you're conversing with in the eyes. Disable the background noise. The sound of a television, for example, can disrupt a discussion. Request that others talk clearly but not too loudly.

When people know you're having problems hearing them, they're usually willing to help.

Acquired hearing loss, which can afflict children at any age after birth, is also a possibility. A variety of factors, including can cause acquired hearing loss
A perforated eardrum
Noise-induced hearing loss is caused by excessive noise exposure.
Otitis media that is untreated or frequently occurs (ear infections)
Toxic exposure from secondhand smoking or other pollutants
Hearing loss can be caused by so many factors, including these four typical causes of temporary hearing loss in children.

When is hearing loss genetic?

Hearing loss can be passed down through the generations, whether or not there is a family history of hearing loss.

Many families with hereditary hearing loss are impacted; in other families, just one member is affected. A genetic alteration could be the reason for your child's hearing loss, even if he or she is the first in your family to be diagnosed.

The goal is for ENT doctors to play a significant role in evaluating children with hearing problems. The group with an unclear cause continues to have a high prevalence.

The goal of this study at Turkey's Afyon School for the Deaf was to figure out what causes deafness. and compare the findings to those of comparative research in Turkey and other countries. Methods: A retrospective examination of 130 deaf students aged 5 to 16 years was conducted in this study.

The children's medical and family histories were acquired. A variety of clinical and laboratory examinations were carried out.

It's all too easy to take our sense of hearing for granted. But, on the other hand, hearing loss is on the rise and is now the third most frequent health problem in the United States. Hearing loss can be caused by various factors, including age, disease, heredity, and other issues like drugs and exposure to loud, continuous noise.

Hearing care professionals at Nebraska Medicine will figure out what's wrong and, if feasible, help you regain some hearing or treat permanent hearing loss with hearing aids or other devices.

A genetic diagnosis can aid physicians in better understanding your child's hearing loss and providing the best treatment options. In addition, your child's doctors can use genetic information to anticipate whether other health concerns may arise or if the hearing loss will alter over time.

What if there is no family history of hearing loss?

If your child’s hearing loss is found to be genetic, genetic testing can be used to determine if other family members carry the genetic change.

This information can be used to help determine the likelihood that family members who carry the genetic change may have a child with hearing loss in the future.

While you may be tempted to wait it out, it’s important to see your doctor right away if you’re experiencing sudden or temporary hearing loss. Early treatment can often mean a better chance at a faster and fuller recovery. Your doctor will review your medical history and perform a physical exam.

He or she may refer you to an ent—a doctor who specializes in ears, nose and throat. Be sure to disclose any medications you’re currently taking, as well as any diagnosed medical conditions you already have.

Idiopathic ssnhl management generates much debate. It must be remembered that this is a diagnosis of exclusion. Idiopathic ssnhl affects approximately 20 per 100 000 people per year and accounts for up to 90% of ssnhl. Tuning fork tests are essential in determining snhl.

A history of the patient describing a clear and sudden change in hearing or awakening with a new hearing loss may help the diagnosis, and treatment can be commenced on a clinical basis.

Depending on the severity and cause of hearing loss in your child, hearing aids, cochlear implants and a combination of speech therapy or assistive listening devices might be recommended forms of treatment. If you notice that your infant or child shows any of the above signs, take him or her to your family doctor, who can refer you to a pediatric audiologist to have your child's hearing tested.

If a child has wax buildup, an ear infection or another problem causing temporary hearing loss, the audiologist will take care of the problem or refer you to an otolaryngologist (ear, nose and throat physician) to have the temporary hearing obstruction treated.

How can a genetic diagnosis help my child?

Advances in genetic engineering will allow for the prediction of diseases and individual features in unborn offspring. However, the amount to which such advances should occur is still a point of contention, posing economic, societal, and ethical issues.

For example, according to this study, while non-deaf pregnant women would value carrier screening for deafness genes and prenatal diagnosis, most would not abort an affected fetus. While further research on public opinion is needed, the lack of consensus in society presents challenges for anyone attempting to make public-opinion-based genetic screening judgments.

Clinically and genetically, hereditary hearing loss is diverse. Over 120 genes have been linked to non-syndromic hearing loss, with many more linked to syndromic hearing loss. Despite the growing number of genes used in regular molecular genetic diagnostics, the diagnostic yield from European patient cohorts with hereditary hearing loss remains about 50%.

This is a reflection of the various knowledge gaps that the field is now attempting to close. Many more genes are likely to be discovered in the future. However, it is to be expected that the mutational fingerprints of known genes, particularly those in non-coding or regulatory areas that alter gene expression, are still unknown.

Should we suspect hearing loss if our infant has a speech and language delay?
“Congenital hearing loss is substantially more common than other metabolic illnesses.”
“The key to management is early diagnosis and treatment.”
“A hereditary component accounts for 50% of congenital hearing loss.”
For hereditary hearing loss, the GC genome offers two types of screening testing.
Why do we require genetic hearing loss screening?

Non-symptomatic hearing loss accounts for 70% of hereditary hearing loss, which has no other symptoms besides hearing loss. As a result, compared to other diseases, it is more difficult to suspect. If the detection period is missed, the child's language development, cognitive capabilities, reading ability, and learning ability may be harmed.

Researchers are investigating other genes that cause Usher syndrome. The initiatives will lead to better genetic counselling and earlier diagnosis, and the possibility of expanding treatment options in the future. Scientists are also working on mice models that mimic the symptoms of Usher syndrome.

Mouse models will be used in research to determine Usher genes' function and inform prospective treatments. Developing novel methods for early detection of children with Usher syndrome, better treatment options for children who utilise hearing aids or cochlear implants to address hearing loss, and trying innovative intervention tactics to delay or stop disease advancement are some of the other areas of research.

How can a genetic diagnosis help my family?

When looking into hearing loss, it's important to distinguish between inherited and acquired (non-genetic) reasons. Otological, audiological, and physical examinations, family history, additional tests (e.g., computed tomography of the temporal bone), and molecular genetic analysis are all required to diagnose hereditary hearing loss.

For many types of syndromal and non-syndromal deafness, molecular genetic testing is accessible. However, it is frequently only for research purposes. Gjb2 and gjb6 testing are essential in clinical diagnosis, and genetic counselling since mutations in these genes cause more than half of severe to profound autosomal recessive non-syndromal deafness in many world populations.

A variety of conditions can contribute to hearing loss that is difficult to identify. However, choosing the proper treatment requires a precise, expert diagnosis.

Hearing loss sufferers are much more likely to manage their symptoms. and attain a high quality of life if they receive an accurate diagnosis.

Hearing loss caused by genetic factors can typically be separated from hearing loss caused by non-genetic (or acquired) factors. Otological, audiological, and physical exams are commonly used to diagnose genetic variants. In addition, the doctor may perform complementary tests or molecular genetic testing. In addition, the doctor may inquire about the affected person's family history.

Hereditary deafness (HD) was studied genetically in Kirov and 10 Kirov oblast counties (administrative region). The research was conducted using audiology, medical genetic counselling, and DNA testing. In 143 children from 100 unrelated households, deafness was discovered to be inherited.

During the study period (1995-2001), the incidence rates of isolated and syndromic hds were estimated to be 1. 25 and 0. 36 per 1000 newborns, respectively, and the total incidence rate of all kinds of HD was 1. 61 per 1000 newborns (1 case per 621 newborns).

Usher syndrome is a hereditary disorder that causes a variety of symptoms retinitis pigmentosa and sensorineural hearing loss (RP). Despite being a rare disorder, it is the most common cause of deafblindness in humans.

Despite the fact that newborn hearing screening has reduced the age at which children with hearing loss are recognised from 12-18 months to 6 months or less (Harrison & Rousch, 1996), Usher syndrome, which causes devastating visual loss, is frequently diagnosed 5-10 years after hearing loss is found (Kimberling & Lindenmuth, 2007).

BAER Test for Hearing Loss

Examinations can be arranged by the family doctor or an ear, nose and throat specialist, depending on local resources and access. Examinations are crucial when the response to treatment is inadequate. The pure tone audiogram is the first audiological test used to distinguish chl from snhl by measuring both air and bone conduction thresholds.

A PTA is used to determine if hearing loss is present and the degree and type of loss. Serial ptas can be used to assess treatment response.

A genetic test is a medical test that looks for genetic changes (mutations) in a person's genetic material, also known as DNA.

The test is usually done with a small sample of blood (2-3 teaspoons). This sample is sent to a diagnostic laboratory that looks for changes in genes most commonly associated with hearing loss. The results of a genetic test can take 3 to 5 weeks to arrive.

To “meet” the SSA list for hearing loss without a cochlear implant, meaning to qualify for disability benefits under the list automatically, you must meet one of two tests. Pure tone and bone conduction audiometry. In your better ear, your average air conduction hearing threshold sensitivity must be 90 decibels (DB) or worse, and your bone conduction hearing threshold must be 60 decibels (DB) or worse.

This indicates a severe hearing loss. Averaging your hearing at sound frequencies of 500 hertz (Hz), 1,000 Hz, and 2,000 Hz is required to compute your hearing loss.

We often take all of the sounds around us for granted., the barking of a dog, the buzzing of a bee or the melody of our favourite symphony. But for many people, the world is a tranquil place. This is because they have lost the ability to hear sounds in one or both ears.

So let's talk about hearing loss. To understand how you lose your hearing, you first need to know what happens typically in your ear when you hear. For example, let's say a fire engine roars by. The siren's sound first reaches your eardrum in the outer ear.

How does genetic testing work?

Identifying the hereditary cause of hearing loss, whether in a child or an older adult, can be time-consuming and challenging. Working with a team of physicians, including a geneticist, an audiologist, an ENT, and a genetic counsellor, can assist speed up the process.

This collaborative approach may even reduce the number of diagnostic tests required. The following are the general responsibilities of your medical team.

As audiologists, diagnosing substantial hearing loss in a child might take up so much of our time that we ignore other limiting conditions. Yet, when dealing with their children who have hearing loss, parents turn to audiologists for advice and assistance.

For example, in their research of family narratives about genetic testing for hearing loss, Steinberg and colleagues (2007) found parental contacts with the audiologist as a critical theme. According to the authors, the audiologist's responsibilities to parents included:

We are providing information about resources.

• Providing assistance and advice through referrals and testing.
• Empowering parents to adjust to their new role.

A variety of non-genetic factors can cause hearing loss. Around half of all hearing loss in newborns and young children is due to these causes. They are as follows:

During pregnancy, the mother may contract some infections.

Infections that the newborn infant is suffering from

Obstacles during or after delivery

several drugs

Hearing loss is sometimes caused by a combination of genes and the environment. However, even after examinations, the source of hearing loss in many babies remains unexplained.

Genetic counselling is required for every infant or toddler diagnosed with bilateral congenital hearing loss with no known explanation (e.g. infectious). For bilateral hearing loss, comprehensive genetic testing gives the greatest diagnostic yield of any single test., with genetic aetiology accounting for up to 60% of cases of congenital hearing loss.

A single gene test, generally for the gjb2 and gjb6 genes, was the only genetic test available for hearing loss at the time. Comprehensive genetic testing (CGT) employing massively parallel sequencing (MPS) or next-generation sequencing (NGS) enhances genetic diagnostic yield by several orders of magnitude over single-gene testing.

It is quickly becoming the new standard of care due to decreasing sequencing costs and eliminating many tests and appointments.

What happens at a genetics appointment?

Most health insurance companies usually cover genetic counselling; it is comparable to visiting a specialist. In many cases, health insurance will cover the cost of genetic testing. However, insurance companies may have different policies on the requirements for genetic testing.

Therefore, it is essential to check with your health insurance company to see if they will cover the cost of the appointment and the test. Once the appropriate genetic test(s) have been identified, a genetics team can also help verify coverage for genetic testing.

The appointment of prominent experts in gene therapy, cochlear development, and molecular genetics to the Scientific Advisory Board of a clinical-stage biotechnology company committed to the discovery and development of transformational treatments to restore and improve hearing and balance was announced today by a clinical-stage biotechnology business committed to the discovery and development of transformational treatments to restore and improve hearing and balance (sab).

“We look forward to working closely with these new additions to our organisation as we progress our pipeline of gene treatments and regenerative medicines,” stated Joe Burns, PhD.

Are genetic counselling and genetic testing covered by insurance?

The Bill Daniels Centre for Children's Hearing currently has money available to cover a portion of the cost of genetic testing suggested by a clinician. In addition, the Genetic Testing Assistance Fund helps families that can't afford to pay the total cost of a test covered by insurance. Each family's subsidy is calculated on an individual basis.

Insurance frequently covers genetic testing. Your genetic counsellor will talk to you about whether your insurance covers the test.

Before the appointment, you do not need to notify your insurance carrier. The laboratory may withhold genetic testing until your insurance verifies coverage for the test. The test will set you back around $600 if you don't have insurance or are a self-pay patient.

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