Psychology Wiki

Genetic counseling: AR Sensorineural Hearing Loss (DFNB1/Connexin 26)

34,203pages on
this wiki
Add New Page
Talk0 Share

Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language | Individual differences | Personality | Philosophy | Social |
Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology |

Clinical: Approaches · Group therapy · Techniques · Types of problem · Areas of specialism · Taxonomies · Therapeutic issues · Modes of delivery · Model translation project · Personal experiences ·

AR Sensorineural Hearing Loss (DFNB1/Connexin 26)


  • Acknowledge prior phone contact
  • What information have you been given already?
  • Have you done any research on your own? What have you found out?
  • What concerns or questions would you like to have answered today?
  • Outline session

Complete Medical HistoryEdit

Complete Family History and PedigreeEdit


  • DFNB1 accounts for 50% of AR sensorineural hearing loss
  • Prevalence is ~14/100,000
    • 1/2000 congenital hearing impairment
    • 70% of these are nonsyndromic
    • 80% of nonsyndromic hearing loss is AR
    • 50% of these are due to GJB2 mutation
  • 1/30 people in general population are carriers


  • Gene: GJB2
  • Chromosome location: 13q11-12
  • Protein: Connexin 26
    • Gap junction protein
    • Involved in conducing signal to the brain
  • Autosomal recessive inheritance
    • 25% risk of hearing loss for future children
    • 50% risk of being a carrier for the mutation
    • 25% risk of being an unaffected noncarrier

Molecular TestingEdit

  • Detects 95% of disease-causing mutations
  • ~66% of mutations - 35delG
  • ~30% of mutations - other GJB2 mutations
  • ~4% mutations - unknown
  • carrier testing is available and can be offered to at-risk family members
  • prenatal testing is available but rarely pursued

Clinical FeaturesEdit

  • nonprogressive sensorineural hearing impairment
    • severe to severe-profound hearing loss
    • diagnosed by Auditory Brainstem Response or pure tone audiometry and presence of no related anomalies
  • no other associated health problems
  • no balance problems


  • When diagnosis is known or suspected
    • Assessment of auditory acuity by ABR or pure tone audiometry
    • Fitting with hearing aids
    • Early intervention
  • Follow-up care
    • semiannual examination by physician familiar with hereditary hearing impairment
    • repeat pure tone audiometry to confirm stability of loss
    • consideration for cochlear implants
  • prelingual deafness associate with decreased cognitive skills and decreased math skills
    • early intervention can help ameliorate these affects

Psychosocial IssuesEdit

  • Deaf child born to hearing parents
  • How did you feel when you first found out?
  • How have your feelings changed?
  • How have other family members reacted?
  • Have you been in contact with any other families?
  • Have you been in contact with any support groups?


  • American Society for Deaf Children
PO Box 3355
Gettysburg, PA 17325
Phone: 717-334-7922
Fax: 717-334-8808
  • National Association of the Deaf
814 Thayer
Silver Spring, MD 20910
Phone: 301-587-1788
Fax: 305-587-1791


  • Geneclinics: Nonsyndromic Hearing Loss and Deafness, DFNB1
  • National Information Center on Deafness
  • Clinical Genetics Lecture


The information in this outline was last updated in 2002.

Material obtained under GFDL Licence from

Heckert GNU white Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License."

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.

Also on Fandom

Random Wiki