Alport Syndrome:Dealing with Hearing Loss and

Advances in TechnologyAbby Meyer M.D.

Assistant Professor, Pediatric Otolaryngology

Director, Lions Children’s Hearing Center

University of Minnesota Department of Otolaryngology

Sensorineural hearing loss

Hearing Loss

Childhood Hearing Loss

Genetic50%

Idiopathic25%

Disease, Treatment Side Effects, Environment

25%

Syndromic1/3

Nonsyndromic2/3

Recessive 75-85%

Dominant 15-24%

X-linked 1-2%

CMV, Herpes, Rubella, Syphilis, Toxoplasmosis, Varicella, Aminoglycosides, Exchange transfusion, Ventilation, ECMO, Fetal Alcohol Syndrome, Lead poisoning, Head trauma.

Hearing Loss

Childhood Hearing Loss

Genetic50%

Idiopathic25%

Disease, Treatment Side Effects, Environment

25%

Syndromic1/3

Nonsyndromic2/3

Recessive 75-85%

Dominant 15-24%

X-linked 1-2%

CMV, Herpes, Rubella, Syphilis, Toxoplasmosis, Varicella, Aminoglycosides, Exchange transfusion, Ventilation, ECMO, Fetal Alcohol Syndrome, Lead poisoning, Head trauma.ALPORT

SYNDROME

Why is there hearing loss associated with Alport Syndrome?• Alport Syndrome is

caused by abnormalities of the COL4A3, COL4A4 or COL4A5 genes, resulting in abnormal type IV collagen

• Type IV collagen is important in the structure and function of the basilar membrane

Characteristics of the hearing loss seen in Alport Syndrome• Hearing loss tends to be:

– SENSORINEURAL– BILATERAL – SYMMETRIC– PROGRESSIVE DURING LATER CHILDHOOD– MIDDLE AND/OR HIGH FREQUENCY– VARIABLE IN DEGREE

• Most patients retain some hearing capacity.

Hearing loss in males vs hearing loss in females with Alport Syndrome

• Significant hearing loss is more common in males than in females – 55% vs 45% but in X-linked Alport Syndrome (mutation

in COL4A5), significant hearing loss develops in 80-90% of affected males by the age of 40.

• In general, hearing loss in affected females tends to occur later in life than in males.

• In general, hearing loss in females may be relatively mild or even subclinical.

But…..• There are no gender differences in the incidence or

course of hearing loss in autosomal recessive Alport Syndrome.

• Hearing loss in autosomal dominant Alport Syndrome tends to be slowly progressive and may not develop until relatively later in life (well into adulthood).

• Characteristics of the genetic abnormality itself can result in different risks for hearing loss (different ages of onset of hearing loss).– Ex: Nonsense vs missense mutations

Management of hearing loss• Monitoring of hearing in patients with Alport

Syndrome is vital– Hearing loss with Alport Syndrome is never

congenital, so it will not be picked up on routine universal newborn hearing screening.

– Audiograms every 1-2 years beginning at age 6 would be a conservative place to start.

– Hearing loss typically becomes detectable by audiogram in late childhood (6-10 years) in boys with X-lined Alport Syndrome and in boys and girls with autosomal recessive Alport Syndrome.

Options

• Sign language• Total communication• Cued speech• Amplification

– Hearing aids– Cochlear implant

• Combinations of technology and various communication can be used

Options• Sign language• Total communication• Cued speech• Amplification

–Hearing aids–Cochlear implant

• Combinations of technology and various communication can be used

Hearing Aids

Cochlear Implantation

• Eligibility criteria– Bilateral moderate to severe sensorineural

hearing loss– Age > 12 months (FDA)

• Many centers implant as young as 6 months• No upper limit on age

– Trial of hearing aids > 6 months• Many centers will decrease time for young children

– Present cochlear nerve– Cochlear anomalies are NOT a contraindication

Cochlear implantation—Postlingual deafness• Postlingually deafened children and adults

tend to do well with cochlear implantation• Duration of deafness correlates with post-

implant performance– Better performance with shorter duration

Cochlear implantation—The process• Internal device

implanted (surgery)

• Wait 3-4 weeks for swelling to subside

• Lots of programming and therapy

Cochlear implant devices

• Parents (patient if adult) work with the audiologist to choose the device

• 3 cochlear implant manufacturers– Cochlear– Advanced Bionics– Med El

Thank you