The effect of GJB2 allele variants on performance after cochlear implantation.
OBJECTIVE
It has been hypothesized that etiology of hearing loss may serve as an independent variable in performance after cochlear implantation. To test this hypothesis, the authors identified pediatric cochlear implant recipients with gap junction protein beta2 (GJB2)-related deafness. The study examines performance outcomes associated with GJB2 deafness-causing allele variants.


METHODS
Pediatric cochlear implant patients were screened for GJB2 allele variants; statistical comparisons were made with prospectively obtained performance measures.


METHODS
From 181 children who participated in a nationwide cochlear implant research program, 122 children were identified with congenital nonsyndromic sensorineural hearing loss and invited to participate. Screening for GJB2 allele variants was completed for 55 children. The children were homogeneous with respect to age (8 or 9 y) and age at implant (before age 5 y). All patients have previously undergone a prospective regimented battery of performance measures.


RESULTS
Performance measures were compared between 22 children with and 33 children without mutations to determine whether GJB2 status was a significant predictor of cochlear implant outcomes. Reading and cognitive outcomes were significantly dependent on connexin status. The group of children who tested positive for GJB2-related deafness scored significantly higher on a nonverbal cognitive measure, Block Design, and on a measure of reading comprehension.


CONCLUSIONS
The isolated insult to the cochlea created by GJB2 allele variants allows for preservation of central cognitive function. Better reading performance is seen in children with GJB2-related deafness.
Bauer
Paul W
PW
Department of Otolaryngology-Head and Neck Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9035, USA. paul.bauer@utsouthwestern.edu
Geers
Ann E
AE
Brenner
Christine
C
Moog
Jean S
JS
Smith
Richard J H
RJ
D000483:Alleles; D002648:Child; D019929:Cochlear Implantation; D003071:Cognition; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D005260:Female; D014644:Genetic Variation; D034381:Hearing Loss / Q000235:genetics* / Q000534:rehabilitation; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011932:Reading; D016896:Treatment Outcome
D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26