Newborn hearing concurrent gene screening can improve care for hearing loss: a study on 14,913 Chinese newborns

Objective: Newborn hearing screening has been widely adopted and made an achievement to some degree. Current screening protocols rely solely on detecting existing auditory disorders at the time of screening and are unable to identify individuals susceptible to auditory disorders in later life. Even if the hearing loss newborn is referred, most cases could not be diagnosed until 6-12 months old with no etiology being elucidated. This study reports the first effort to combine traditional hearing screening with genetic screening to improve the efficacy of newborn hearing screening.

Methods: This study was undertaken in 12 regional hospitals located in 11 provinces of China. 14,913 newborn babies received hearing concurrent genetic screening. The hearing screening was performed with OAE or AABR. Blood sample was collected with a universal newborn genetic screening card. And three common gene, mtDNA 12S rRNA, GJB2 and SLC26A4 were screened with standard protocol.

Results: Among all the 14,913 newborns, 86.1% (12,837/14,913) individuals passed the first-step hearing screening, 7.8% (1168/14,913) babies passed only one side, and the other 6.1% (908/14,913) were bilaterally referred. Gene screening found 306 individuals had one or two mutant alleles, the carrier rate is 2.05% (306/14,913) among the entire newborn population. The risk for hearing loss was 100% (7/7) for those newborns carrying causative GJB2 or SLC26A4 mutations (homozygotes or compound heterozygotes), 14.4% (23/160) for GJB2 heterozygote carriers, 12.3% (15/122) for SLC26A2 heterozygous carriers, and the total prevalence of referral hearing screening was approximately 14.7% (45/306). However, 85.3% (261/306) newborns passed hearing screening among these carriers including 18 newborns with 12S rRNA mt.1555A>G pathogenic mutation, who would suffer from sudden hearing loss once applying aminoglycoside drugs.

Conclusion: The cohort studies provided the essential population parameters for developing effective programs for hearing care of newborns in China. Hearing concurrent gene screening in newborns may confirm the abnormal results from hearing screening tests, help to find the etiologic of the hearing loss, and better recognize infants at risk for late-onset hearing loss occurring prior to speech and language development. In conclusion, a survey on 14,913 Chinese newborns proved that concurrent genetic screening could improve newborn hearing screening for hearing defects.