Infant hearing loss and connexin testing in a diverse population.
OBJECTIVE
Previous studies of connexin-related hearing loss have typically reported on mixed age groups or adults. To further address epidemiology and natural history of connexin-related hearing loss, we conducted a longitudinal study in an ethnically diverse cohort of infants and toddlers under 3 years of age. Our study compares infants with and without connexin-related hearing loss to examine differences in the prevalence of connexin and non-connexin-related hearing loss by ethnic origin, detection by newborn hearing screening, phenotype, neonatal risk factors, and family history. This is the first study to differentiate infants with and without connexin-related hearing loss.


METHODS
We enrolled 95 infants with hearing loss from whom both exons of Cx26 were sequenced and the Cx30 deletion was assayed. Demographic, family history, newborn hearing screening data, perinatal, and audiologic records were analyzed.


RESULTS
Genetic testing identified biallelic Cx26/30 hearing loss-associated variants in 24.7% of infants with a significantly lower prevalence in Hispanic infants (9.1%). Eighty-two infants underwent newborn hearing screening; 12 infants passed, 3 had connexin-related hearing loss. No differences in newborn hearing screening pass rate, neonatal complications, or hearing loss severity were detected between infants with and without connexin-related hearing loss. Family history correlates with connexin-related hearing loss.


CONCLUSIONS
Connexin-related hearing loss occurs in one quarter of infants in an ethnically diverse hearing loss population but with a lower prevalence in Hispanic infants. Not all infants with connexin-related hearing loss fail newborn hearing screening. Family history correlates significantly with connexin-related hearing loss. Genetic testing should not be deferred because of newborn complications. These results will have an impact on genetic testing for infant hearing loss.
Schimmenti
Lisa A
LA
Department of Pediatrics, Institute of Human Genetics, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA. las@umn.edu
Martinez
Ariadna
A
Telatar
Milhan
M
Lai
Chih-Hung
CH
Shapiro
Nina
N
Fox
Michelle
M
Warman
Berta
B
McCarra
Matthew
M
Crandall
Barbara
B
Sininger
Yvonne
Y
Grody
Wayne W
WW
Palmer
Christina G S
CG
D001299:Audiometry; D002140:California / Q000453:epidemiology; D000072259:Connexin 26; D000075302:Connexin 30; D017630:Connexins / Q000235:genetics*; D017931:DNA Primers; D014644:Genetic Variation; D034381:Hearing Loss / Q000453:epidemiology* / Q000208:ethnology / Q000235:genetics*; D006630:Hispanic or Latino / Q000235:genetics; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D015995:Prevalence; D012307:Risk Factors; D017422:Sequence Analysis, DNA
D000075302:Connexin 30; D017630:Connexins; D017931:DNA Primers; C000607042:GJB2 protein, human; C491020:GJB6 protein, human; D000072259:Connexin 26