Pendred Syndrome and EVA Hearing Loss (SLC26A4): What a 2,774-Patient Study Shows

Pendred Syndrome and EVA Hearing Loss (SLC26A4): What a 2,774-Patient Study Shows

This article is for educational purposes only. It is not a substitute for advice from a licensed physician, board-certified medical geneticist, or board-certified genetic counselor. For any decisions about testing, treatment, or care, consult a qualified clinician. In emergencies, call 911.

Bottom line: The largest study of this condition so far followed 2,774 people with an enlarged vestibular aqueduct. About 36 in 100 of the children with screening records had passed their newborn hearing test. About 43 in 100 had repeated dizzy spells, but only about 6 in 100 had a goiter. So a “pass” at birth does not rule this out, and regular hearing checks matter. A 23andMe carrier report, which the company lists as checking 6 variants, cannot diagnose or fully clear anyone. No therapy made for this condition is approved in the US or Canada.

What you’ll learn

• What Pendred syndrome, DFNB4, and enlarged vestibular aqueduct (EVA) are, and how they connect to one gene
• Why hearing can be normal at birth, then rise and fall over the years
• What a 23andMe carrier result, a single variant, or a “VUS” can and cannot tell you
• How families plan care, testing for relatives, and legal protections in the US and Canada

1. What Pendred syndrome, DFNB4, and enlarged vestibular aqueduct are (and how they differ from GJB2 hearing loss)

Pendred syndrome is a genetic condition with two main features. The first is hearing loss. The second is a goiter, which is an enlarged thyroid gland in the neck.

Most people with Pendred syndrome also have an enlarged vestibular aqueduct (EVA). The vestibular aqueduct is a tiny bony canal in the inner ear. It counts as enlarged if it is wider than one millimeter, about the size of a pinhead. From here on, this article calls it “the canal.” Some people also have a cochlea with an unusual shape. EVA plus that cochlear shape is called a Mondini malformation.

Some people have the same hearing pattern and the wide canal, but no thyroid changes. Doctors call this nonsyndromic hearing loss, or DFNB4. GeneReviews, a medical reference from the University of Washington, now groups both under one name: SLC26A4-related hearing loss.

One gene, one protein, two organs

The SLC26A4 gene holds the instructions for a protein called pendrin. Pendrin works like a small gate. It moves salts such as chloride, iodide, and bicarbonate in and out of cells. It works in two places: the inner ear and the thyroid. That is why one gene can affect both hearing and the neck.

A simple analogy: think of the inner ear as a fish tank that needs the right water balance. Pendrin is part of the pump that keeps that balance. When the pump is faulty, the delicate hearing cells in the “tank” can slowly suffer.

How common it is

Measure	Figure	Plain-language version	Source
Share of hearing loss present from birth caused by Pendred syndrome	7 to 8 percent	About 7 or 8 in 100 babies born with hearing loss
Share of Pendred syndrome cases traced to SLC26A4	About half	About 50 in 100 cases
Children with sensorineural hearing loss who have EVA	5 to 15 percent	About 5 to 15 in 100
People with EVA and hearing loss who have Pendred syndrome	About one-fourth	About 25 in 100

Sensorineural hearing loss means the problem sits in the inner ear or hearing nerve, not in the ear canal or eardrum. In many Asian countries, SLC26A4 changes are the second most common genetic cause of hearing loss.

How this differs from GJB2 hearing loss

GJB2 (also called DFNB1) is a different gene and the most familiar cause of genetic hearing loss. Its course is usually stable. SLC26A4 hearing loss often changes over time, may come with dizziness, and can involve the thyroid. That is why EVA needs its own follow-up plan. GeneLumen covers GJB2 and Usher syndrome in separate articles in the Neurogenetic Diseases category.

If a scan report mentions EVA or a Mondini malformation, ask the ENT doctor (ear, nose, and throat specialist) what it means for the child’s follow-up.

Section recap: Pendred syndrome and DFNB4 are two faces of one gene, SLC26A4, and the wide inner-ear canal (EVA) is their hallmark. The thyroid part is what separates Pendred syndrome from DFNB4.

2. How SLC26A4 is inherited: autosomal recessive, carriers, and the “one variant” puzzle

SLC26A4 conditions follow autosomal recessive inheritance. That means a child needs two altered copies of the gene, one from each parent, to be affected. A carrier is a person with one altered copy and one working copy. Carriers usually have no signs at all.

The odds for each pregnancy

When both parents are carriers, the odds are the same for every pregnancy.

Outcome for each pregnancy	Chance	Plain-language version
Child is affected (two altered copies)	25%	About 1 in 4
Child is a carrier (one altered copy)	50%	About 2 in 4
Child has two working copies	25%	About 1 in 4

These odds reset with each pregnancy. Think of a coin flip: the coin has no memory. Having one affected child does not make the next child more or less likely to be affected.

If only one parent is a carrier, children are not expected to have the recessive form. Each child would have about a 50 in 100 chance of being a carrier. A genetic counselor can confirm this for your family.

The “one variant” puzzle

Many families hear a confusing result. Their child clearly has EVA, yet testing finds only one altered copy, or none.

NIH researchers studied this in 71 families. They compared families with two, one, or zero detected variants. Families with one variant passed on EVA at rates similar to families with two.

That pattern suggests a second, hidden change in the same gene. Families with zero variants looked different. Their EVA may have other causes, including other genes or non-genetic factors.

The 2025 study of 2,774 patients helped solve part of this puzzle. Researchers looked beyond the usual parts of the gene.

Finding in the 2025 cohort	Count	Plain-language version
Two SLC26A4 variants found	2,661 of 2,774 (95.9%)	About 96 in 100
One variant was a deletion or duplication of gene pieces	70 (2.5%)	About 2 or 3 in 100
One variant was a deep-inside-the-gene change (c.304+941C>T)	13 (0.5%)	About 1 in 200
A change in a different gene, FOXI1	1 family	Rare

A deletion or duplication is a missing or extra chunk of DNA. Standard tests that read the gene letter by letter can miss these. The same is true for changes buried deep inside the gene, outside the parts that are normally read.

One caution matters here. This study came from a single hospital in China. The common variants differ between populations. So North American numbers may not match exactly.

A genetic counselor can explain which kind of testing found, or missed, a second variant. You can find one through the National Society of Genetic Counselors.

Section recap: Two carrier parents have a 1-in-4 chance with each pregnancy of having an affected child. A “one variant” result with EVA often means a second change is hiding where basic tests do not look.

3. What the hearing course looks like: newborn screening, fluctuating and progressive loss, and vertigo

This is the section most parents want first. The short answer is that hearing in EVA often changes over time. It can drop in steps, partly recover, and drop again.

Passing the newborn screen does not rule it out

In the 2025 cohort, 341 patients had newborn screening records. Of those, 124 had passed (36.36%). Put simply, about 36 in 100 children later found to have EVA had passed their newborn hearing test.

GeneReviews explains why. Hearing loss can start at different ages, so some newborns pass. But by age 3, most children with SLC26A4 hearing loss have severe to profound loss in both ears.

The CDC sets the US newborn hearing plan as “1-3-6”:

• Screen before 1 month of age
• Full hearing test before 3 months if the baby does not pass
• Start early intervention services before 6 months

The CDC also says children at risk of late-onset or worsening hearing loss should have at least one more hearing test by about age 2 to 2.5. This framework comes from the Joint Committee on Infant Hearing, which guides US Early Hearing Detection and Intervention (EHDI) programs. A newborn “pass” is a snapshot, not a lifetime guarantee. It is like a photo of the weather on one day; it does not forecast next year.

How hearing changes over time

Feature	What studies report	Source
Hearing over time	Pendred-related hearing loss is usually progressive
Profound loss	52.0% of 608 tested ears (about half) in a Japanese national survey
Uneven ears	Loss differed between ears in 48.4% of 304 patients
Sudden drops after a cold	5.0% of patients
What predicts severity	Number of altered gene copies, not the shape on the scan

The last row deserves a closer look. In an NIH study of 83 people, ears with EVA in people with two altered copies had worse hearing than ears in people with one or none. The shape of the cochlea on CT or MRI did not track with hearing level. So the gene result can help predict hearing better than the scan picture.

Dizziness and balance

In the 2025 cohort, 256 of 597 patients reported repeated vertigo (42.9%). Vertigo is a spinning type of dizziness. That is about 43 in 100 people.

In young children, balance problems can look different. GeneReviews lists head-tilting, vomiting, late walking, or new clumsiness. These signs can come before or along with a change in hearing. Still, the NIDCD notes that most children with EVA do not have balance problems that affect daily tasks.

Head injury: what is known and what is not

A Japanese survey of 380 EVA patients found that 5.3% had a sudden hearing drop after a head injury. That is about 5 in 100 patients. A past head injury was also linked with fluctuating hearing or vertigo. This is an association from a survey. It does not prove that the injury caused the drop.

The NIDCD advises people with EVA to avoid contact sports that could cause a head injury. It also suggests helmets for biking or skiing and avoiding sudden pressure changes, such as scuba diving.

GeneReviews takes a more cautious view. It says the evidence is not strong enough to show that avoiding contact sports lowers the overall risk of hearing loss getting worse. Families are encouraged to weigh this and decide for themselves.

Treat these steps as precautions, not proven prevention. Talk through sports and activity choices with the child’s ENT doctor and audiologist (a hearing-test specialist).

Section recap: About 36 in 100 children with EVA passed their newborn screen, and about 43 in 100 later had vertigo. Hearing often worsens in steps, so regular hearing tests are the key safety net.

4. The thyroid side: goiter timing, the perchlorate test, and when hypothyroidism matters

The thyroid part of Pendred syndrome often shows up later than the hearing part. It also tends to be milder than many parents fear.

When a goiter appears

MedlinePlus says a goiter, if it develops, usually forms between late childhood and early adulthood. GeneReviews places it most often in the teen years, ages 10 to 19. In most cases, the goiter does not make the thyroid malfunction.

In the 2025 cohort, only 38 of 597 patients had a goiter (6.4%). That is about 6 in 100. So most people with EVA in that study did not show the thyroid feature.

Diet may matter too. GeneReviews notes that thyroid changes are found more often in countries without universal salt iodization. Iodine helps the thyroid make its hormones. Ask your doctor before changing any diet or supplement.

What thyroid checks look like

Check	What it shows	Notes
Neck exam	Whether the thyroid feels enlarged	Part of a routine visit
Thyroid blood tests (TSH, thyroxine)	Whether the gland makes enough hormone	In an NIH study, results did not track with the number of altered copies
Thyroid ultrasound	Size of the gland	GeneReviews suggests a first scan at age 10, then every 5 to 10 years
Perchlorate discharge test	How well the thyroid holds iodine	Older test; mainly used in special cases

An NIH study of 80 people with EVA looked closely at the thyroid. In children, thyroid size depended mostly on the gene result. In older patients, it depended more on age. People with two altered copies released more iodine on the perchlorate test.

The perchlorate test gives a small dose of a tracer that shows how well the gland holds on to iodine. In 2009, the NIH authors suggested it for people with EVA plus a goiter, or with unclear gene results. That was a research team’s view at the time. It is not routine for every patient today.

Some people with Pendred syndrome do develop hypothyroidism, which means the thyroid makes too little hormone. A pediatrician or endocrinologist (a hormone specialist) can decide how often to check thyroid levels.

Section recap: A goiter, if it comes at all, usually appears in the teen years and most often leaves thyroid function normal. Periodic neck checks, and blood tests when advised, keep this side covered.

5. Testing options in the US and Canada: diagnostic panels vs the 23andMe 6-variant carrier report

There are two very different ways people learn about SLC26A4. One is clinical testing ordered by a doctor. The other is a direct-to-consumer (DTC) kit bought online.

The clinical path

When a child has hearing loss, the workup usually has three parts:

• Hearing tests by an audiologist, repeated over time
• Imaging with CT or MRI of the inner ear, which shows the wide canal
• Genetic testing that looks at many hearing-loss genes at once

The American College of Medical Genetics and Genomics (ACMG) published a 2022 resource on finding the cause of hearing loss. It explains that knowing the cause can change care, sharpen the outlook, and guide advice for relatives. It also calls for services that respect Deaf and hard-of-hearing language and culture.

GeneReviews states that a diagnosis requires two disease-causing SLC26A4 variants on molecular testing. As Section 2 showed, a full search may need methods that find deletions and deep changes. When testing is medically needed, US health plans often cover it, but coverage varies. Ask the clinic to check with your insurer first.

The 23andMe carrier report

According to 23andMe’s own clinician listing, its Carrier Status report for “Pendred Syndrome and DFNB4 Hearing Loss” checks 6 variants in SLC26A4. This is a company product listing, not a medical study. The page could not be re-checked on the day this article was prepared, so treat the exact count as the company’s own claim.

Question	Clinical genetic testing	23andMe Carrier Status report
Who orders it	A doctor or genetic counselor	The consumer
How much of the gene it reads	Usually the whole coding gene, often with deletion checks	A small set of known spots (6, per 23andMe)
Can it diagnose a child’s hearing loss	Yes, with two disease-causing variants	No
Can it rule out carrier status	Much more thorough, but no test is perfect	No
What a positive result needs	Review with the care team	Confirmation by clinical testing

Here is an everyday picture. The gene is like a long book.

A clinical panel reads most of the pages. The kit checks a handful of specific words. If the kit finds a misspelled word, that matters. If it does not, the rest of the book is still unread.

Doctors can also order expanded carrier screening for people planning a pregnancy. A genetic counselor can explain which options fit a family’s situation.

Section recap: Clinical gene panels, ordered alongside hearing tests and imaging, are the route to a diagnosis. A DTC kit result is a starting point for a conversation, not an answer.

6. Reading your results: two variants, a single variant, a VUS, and a negative

Gene results come in a few common forms. Each one means something different. The table below gives the general idea. Your own report should be reviewed with a professional.

Result	What it usually means	Common next step
Two disease-causing variants, one on each copy	Supports the diagnosis	Plan hearing, balance, and thyroid follow-up; offer testing to relatives
One variant plus EVA on imaging	A second change may be hidden	Ask about deletion and deep-gene testing
One variant, no hearing loss (for example, from a kit)	Likely a carrier with no signs	Clinical confirmation; consider partner testing
VUS	Meaning not yet known	Not used alone for decisions; may be updated later
Zero variants on a kit	Lower chance, but not zero	Residual risk remains

A VUS, or variant of uncertain significance, is a gene change that science cannot yet label as harmful or harmless. Labs may reclassify a VUS as more data comes in. It is fine to ask the lab or counselor whether they will send an update.

Why the number of copies matters for hearing

Recall the NIH finding from Section 3. People with two altered copies had worse hearing in EVA ears than those with one or none. The authors suggested the number of altered copies is useful for counseling about the likely course. Even so, each child’s path varies. No result can predict exact hearing levels years ahead.

A zero-variant EVA result

Some children have EVA but no SLC26A4 variant found at all. In the NIH family study, EVA in some of these families did not travel with the gene region. That suggests other causes. The 2025 cohort found one family with a change in a different gene, FOXI1. A geneticist can decide whether broader testing, such as a larger panel, makes sense.

Bring the printed report to a genetic counselor, ENT doctor, or audiologist. A result read alone, late at night, is easy to misread.

Section recap: Two variants support a diagnosis, one variant with EVA calls for a deeper search, and a VUS or a zero-variant kit result is not a final answer. A professional review turns a report into a plan.

7. Care and the treatment landscape: hearing aids, cochlear implants, vestibular care, and research therapies

There is no cure yet. But there is a lot that helps children hear, talk, and learn well.

Approval status as of October 2026

Therapy	Status	Source
Any drug or gene therapy made for Pendred syndrome or DFNB4	Not approved by the FDA or Health Canada
Low-dose sirolimus	Early trial protocol in Japan; no results reported in the protocol paper; sirolimus is approved only for other uses
SLC26A4 gene therapy	Tested in mice only; not available to patients

The NIDCD states that no treatment has been proven to reduce EVA-related hearing loss or slow its progression. Steroids for sudden hearing loss have not been backed by studies in EVA. Surgery on the inner ear’s fluid sac is not effective and can be harmful.

Standard care today

• Hearing aids for mild to severe hearing loss
• Cochlear implants when hearing aids give limited benefit. A cochlear implant is a surgically placed device that sends sound signals straight to the hearing nerve. Surgeons expect possible fluid leaks during the operation. Short-term dizziness afterward is the most common side effect.
• Regular hearing tests: GeneReviews suggests every 3 to 6 months until age 3, then once a year
• Balance checks if a child has dizzy spells or new clumsiness
• Thyroid follow-up as described in Section 4
• School support, such as seating near the teacher, sound systems, or sign language services

Early support matters. The CDC aims for early intervention services before 6 months of age when hearing loss is found.

Research to watch, honestly framed

Gene therapy in mice. A 2026 study in the Journal of Clinical Investigation tested a gene therapy in mice with SLC26A4 changes. The team delivered a working copy of the gene using a harmless virus shell. When given early in life, the treatment lowered hearing thresholds and protected hearing cells. The effects lasted into adulthood.

There are no human data yet. The study was partly sponsored by a company that supplied the virus shells, and a related patent was filed.

Low-dose sirolimus. A team at Keio University in Japan published a plan for an early trial in 2020. Sirolimus is an existing drug used for other conditions. In lab tests, it reduced cell death in inner-ear cells grown from patients’ own stem cells.

The plan involved 16 patients aged 7 to 50 with fluctuating hearing. Its main goal was to check safety. The paper reported no results on whether the drug works.

Think of these like a new bridge design tested in a model. The model is promising, but no one can drive on it yet. Ask the child’s ENT doctor about clinical trials before seeking any treatment abroad.

Section recap: No therapy made for Pendred syndrome is approved by the FDA or Health Canada. Hearing aids, cochlear implants, regular checks, and school support are the proven tools today.

8. Family planning, telling relatives, and legal protections (GINA and Canada’s GNDA)

A gene result affects more than one person. It can raise questions about brothers and sisters, future babies, and insurance.

Testing relatives

Cascade testing means offering gene tests to blood relatives after one person’s variants are found. Once both of a child’s variants are known, these options open up:

• Siblings of an affected child can be tested, ideally soon after birth, so hearing support can start early
• Relatives of carrier parents, such as aunts and uncles, can learn whether they are carriers
• Partners can be tested before a future pregnancy
• Prenatal or preimplantation testing is possible for families who want it

Preimplantation testing means checking embryos created through IVF before one is placed in the uterus. These are personal choices. A genetic counselor’s role is to explain options without pushing any of them.

US protections: GINA

The Genetic Information Nondiscrimination Act of 2008 (GINA) protects Americans in two areas:

Area	What GINA does	Limits
Health insurance (Title I)	Bars use of genetic information by private plans, Medicare, Medicaid, and others	Weaker for TRICARE
Employment (Title II)	Bars use in hiring, firing, pay, and promotion; limits employer requests	Does not apply to the US military
Life, disability, long-term care insurance	Not covered	Some states add protections

So a carrier result cannot legally be used by an employer or a health insurer in the US. It could be relevant if someone applies for life insurance. Some families time their testing with this in mind.

Canada’s protections: GNDA

Canada’s Genetic Non-Discrimination Act of 2017 works differently. No one may require a genetic test, or the results, as a condition for goods, services, or contracts.

No one may collect or use test results in those settings without written consent. This covers contracts beyond health insurance, such as other insurance. Fines can reach $1,000,000.

Feelings and identity

Parents often feel guilt after learning they passed on a variant. Carriers did nothing to cause their status, and most carriers never know until a test or a diagnosis in the family.

Some families are part of the Deaf community or connect with it. For many Deaf people, deafness is tied to language and culture. The ACMG asks that genetic services respect this identity. Choices about hearing aids, implants, and sign language belong to each family.

A genetic counselor can help with telling relatives and with feelings that come up along the way.

Section recap: Once a child’s two variants are known, siblings, relatives, and partners can be offered testing. GINA guards US health insurance and jobs, while Canada’s GNDA covers a wider range of contracts.

FAQ

Can a child who passed the newborn hearing test still have EVA or Pendred syndrome?

Yes. In the 2025 cohort, about 36 in 100 children with screening records had passed. Hearing loss can start or worsen after birth. Keep up with follow-up hearing tests, and tell the pediatrician if speech or hearing seems to change.

Does a carrier result mean the parent will lose hearing?

Usually not. Carriers have one altered copy and one working copy, and they typically have no signs. The main meaning is for future children. If a partner is also a carrier, each pregnancy has about a 1 in 4 chance of an affected child.

Will the other children inherit this?

Each brother or sister of an affected child has the same odds: about 1 in 4 affected, 2 in 4 carriers, and 1 in 4 with two working copies. Testing soon after birth is an option once the family’s variants are known.

Can this result affect health insurance, life insurance, or a job?

In the US, GINA blocks genetic discrimination by health insurers and employers. It does not cover life, disability, or long-term care insurance. In Canada, the GNDA bars requiring or using genetic test results for contracts and services without consent.

Is a second opinion worth it?

Often, yes, especially if only one variant was found despite clear EVA on a scan. Wider testing can find hidden changes in some families. A board-certified genetic counselor or medical geneticist can review the report and suggest next steps.

Summary

• Pendred syndrome and DFNB4 come from changes in one gene, SLC26A4, and share a wide inner-ear canal (EVA).
• About 36 in 100 children with EVA in a 2,774-patient study had passed newborn screening. Regular hearing tests matter.
• Hearing often worsens in steps, and about 43 in 100 had repeated vertigo. Head-injury precautions are advice, not proven prevention.
• A goiter affected about 6 in 100 and usually leaves thyroid function normal.
• Two carrier parents have a 1-in-4 chance per pregnancy of an affected child.
• A 6-variant kit result cannot diagnose or fully rule out carrier status.
• No FDA- or Health Canada-approved therapy exists for this condition; gene therapy is still in mice.

Hearing tests, an ENT doctor, and a genetic counselor form the core team. Start with whichever one is easiest to reach.

This article is for educational purposes only. It is not a substitute for advice from a licensed physician, board-certified medical geneticist, or board-certified genetic counselor. For any decisions about testing, treatment, or care, consult a qualified clinician. In emergencies, call 911.

References

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2. MedlinePlus Genetics, U.S. National Library of Medicine. Pendred syndrome. https://medlineplus.gov/genetics/condition/pendred-syndrome/
3. National Institute on Deafness and Other Communication Disorders (NIH). Enlarged Vestibular Aqueducts and Childhood Hearing Loss. https://www.nidcd.nih.gov/health/enlarged-vestibular-aqueducts-and-childhood-hearing-loss
4. King KA, Choi BY, Zalewski C, et al. SLC26A4 genotype, but not cochlear radiologic structure, is correlated with hearing loss in ears with an enlarged vestibular aqueduct. Laryngoscope. 2010;120(2):384-389. https://pubmed.ncbi.nlm.nih.gov/19998422/
5. Choi BY, Madeo AC, King KA, et al. Segregation of enlarged vestibular aqueducts in families with non-diagnostic SLC26A4 genotypes. J Med Genet. 2009;46(12):856-861. https://pubmed.ncbi.nlm.nih.gov/19578036/
6. Madeo AC, Manichaikul A, Reynolds JC, et al. Evaluation of the thyroid in patients with hearing loss and enlarged vestibular aqueducts. Arch Otolaryngol Head Neck Surg. 2009;135(7):670-676. https://pubmed.ncbi.nlm.nih.gov/19620588/
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8. Smith RJH, Azaiez H, Odell AM. SLC26A4-Related Sensorineural Hearing Loss. GeneReviews (University of Washington; NCBI Bookshelf), updated April 3, 2025. https://www.ncbi.nlm.nih.gov/books/NBK1467/
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10. Joint Committee on Infant Hearing. Year 2019 Position Statement: Principles and Guidelines for Early Hearing Detection and Intervention Programs. J Early Hear Detect Interv. 2019;4(2):1-44. https://digitalcommons.usu.edu/jehdi/vol4/iss2/1/
11. U.S. Centers for Disease Control and Prevention. Hearing Loss in Children: Hearing Screening. https://www.cdc.gov/hearing-loss-children/screening/index.html
12. U.S. Equal Employment Opportunity Commission. Genetic Information Discrimination. https://www.eeoc.gov/genetic-information-discrimination ; National Human Genome Research Institute (NIH). Genetic Discrimination. https://www.genome.gov/about-genomics/policy-issues/Genetic-Discrimination
13. Government of Canada, Justice Laws Website. Genetic Non-Discrimination Act, S.C. 2017, c. 3. https://laws-lois.justice.gc.ca/eng/acts/G-2.5/FullText.html
14. Tsai YH, Wu PY, Chuang YC, et al. Postnatal Slc26a4 gene therapy improves hearing and structural integrity in a hereditary hearing loss model. J Clin Invest. 2026;136(8):e193812. https://pubmed.ncbi.nlm.nih.gov/41701544/
15. Fujioka M, Akiyama T, Hosoya M, et al. A phase I/IIa double blind single institute trial of low dose sirolimus for Pendred syndrome/DFNB4. Medicine (Baltimore). 2020;99(19):e19763. https://pubmed.ncbi.nlm.nih.gov/32384426/
16. 23andMe. Carrier Status genetic reports listing for clinicians (company page). https://www.23andme.org/clinicians/genetic-reports/carrier-status/

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Last updated: 2026-10-22

Author: Yu Mizuno (Editor-in-Chief, non-physician), GeneLumen editorial team. This article aggregates 16 sources from peer-reviewed medical literature and public health agencies (tier 1=12 / tier 2=3, plus one company product listing), including MedlinePlus, the NIDCD and NHGRI (NIH), the CDC, the US Equal Employment Opportunity Commission, Canadian federal law, GeneReviews, the American College of Medical Genetics and Genomics, the Joint Committee on Infant Hearing, and PubMed-indexed cohort studies and laboratory research.

This article is for educational purposes only and is not a substitute for medical advice from a licensed physician, board-certified medical geneticist, or board-certified genetic counselor. In emergencies, call 911 (US/Canada) or 119 (Japan).

Related: Neurogenetic Diseases

🇯🇵 For readers in Japan — a separate Japanese edition written for Japan’s healthcare system (not a translation): https://genelumen.com/ja/ja-neurogenetic/pendred-syndrome-slc26a4-eva-ja