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Updated: May 17, 2026
09:56
Cochlear Implantation in the Guinea Pig
Published on: June 15, 2018
Two portuguese cochlear implanted dizygotic twins: a case report
Joana Rita Chora1, Helena Simões-Teixeira, Tiago Daniel Matos
1Center for Biodiversity, Functional and Integrative Genomics, Faculty of Science, University of Lisbon, 1749-016 Lisbon, Portugal.
Case Reports in Genetics
|October 18, 2012
Summary
Environmental factors significantly impact hearing outcomes in children with cochlear implants (CI), even with similar genetic backgrounds for deafness. Early intervention and tailored support are crucial for optimal auditory development.
Area of Science:
- Genetics
- Audiology
- Neuroscience
Background:
- Hearing performance after cochlear implantation (CI) varies due to factors like deafness etiology, age at implantation, and the home environment.
- This study examines dizygotic twins with profound neurosensorial deafness who received cochlear implants at 3.5 years old.
Purpose of the Study:
- To investigate the genetic causes of deafness in a family with dizygotic twins.
- To compare the auditory and oral rehabilitation outcomes in the twins post-cochlear implantation.
- To determine the influence of genetic versus environmental factors on CI outcomes.
Main Methods:
- Clinical and genetic characterization of the family.
- Auditory, speech, and language assessments using a battery of tests.
- Genetic analysis including GJB2 and GJB6 gene sequencing.
Main Results:
- The genetic cause of deafness was identified, involving mutations in the GJB2 and GJB6 genes.
- The dizygotic twins exhibited notable differences in auditory and oral performance after cochlear implantation.
- The twin girl was homozygous for a GJB2 mutation, while the twin boy was a compound heterozygote for GJB2 and GJB6 mutations.
Conclusions:
- Environmental factors, specifically the differing home environments of the twins, are likely the primary drivers of their varied post-CI outcomes.
- Genetic background plays a role, but environmental influences may be more significant in shaping auditory and speech development after cochlear implantation.
- This case highlights the complex interplay between genetics and environment in pediatric hearing rehabilitation.
Related Concept Videos
01:13The Cochlea
The cochlea is a coiled structure in the inner ear that contains hair cells—the sensory receptors of the auditory system. Sound waves are transmitted to the cochlea by small bones attached to the eardrum called the ossicles, which vibrate the oval window that leads to the inner ear. This causes fluid in the chambers of the cochlea to move, vibrating the basilar membrane.
01:31Hearing
When we hear a sound, our nervous system is detecting sound waves—pressure waves of mechanical energy traveling through a medium. The frequency of the wave is perceived as pitch, while the amplitude is perceived as loudness.