Diagnostic yield in the workup of congenital sensorineural hearing loss is dependent on patient ethnicity.
OBJECTIVE
Diagnostic yield on GJB2 sequencing and computed tomography in the workup for idiopathic congenital sensorineural hearing loss is related to patient ethnicity.


BACKGROUND
GJB2 sequencing and computed tomography of the temporal bones are important initial diagnostic tests in the workup of idiopathic congenital sensorineural hearing loss. Previous studies showed an association between mild or unilateral hearing loss and positive imaging findings and between severe or bilateral deafness and GJB2 mutations. Recent studies on connexin 26-associated deafness demonstrate a wide range of phenotypes that vary with ethnicity.


METHODS
We present a retrospective case series of 271 consecutive ethnically diverse patients evaluated for idiopathic congenital sensorineural hearing loss. Results of genetic testing and imaging were correlated with audiologic findings and ethnicity.


RESULTS
All patients with asymmetric hearing loss had more positive findings on imaging. With respect to the severity of hearing loss, however, differences were noted between ethnic groups. Whereas white patients conformed to previous findings, Hispanics with severe hearing loss had similar rates of positive imaging and genetic testing results. Asians with mild hearing loss had significantly greater yield on genetic testing rather than on imaging. This reflects the high prevalence of the p.V37I mutation in GJB2 among Asians, which gives rise to a mild, frequently progressive phenotype.


CONCLUSIONS
Ethnicity should be considered when determining the optimal sequence of diagnostic testing for idiopathic congenital sensorineural hearing loss. Asian patients, in particular, should all be screened for mutations in GJB2, especially in the case of mild hearing loss.
Department of Otolaryngology-Head and Neck Surgery, Lucille Packard Children's Hospital, Stanford University Hospital and Clinics, Stanford, California 94305, USA. dylan.k.chan@gmail.com
Dylan K
DK
Chan
Iris
I
Schrijver
Kay W
KW
Chang
D000483:Alleles; D001299:Audiometry; D002648:Child; D002675:Child, Preschool; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D005006:Ethnicity / Q000235:genetics*; D005787:Gene Frequency; D005838:Genotype; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis* / Q000208:ethnology / Q000235:genetics; D006801:Humans; D012189:Retrospective Studies; D018709:Statistics, Nonparametric
D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26