Auditory screening concurrent deafness predisposing genes screening in 10,043 neonates in Gansu province, China

Objective: The aim of our study was to evaluate the effectiveness of combining newborn hearing screening with screening for genetic mutations associated with deafness.

Methods: Ten thousand forty-three newborn babies, born between December 2009 and April 2011 in Gansu province, China, were screened for hearing loss using the otoacoustic emissions test or automatic auditory brainstem response test and genetic mutations associated with deafness using a standard protocol.

Results: In the hearing screening, the referral rate for hearing loss in the first-step screening was 14.4% (1409/9786), decreasing significantly to 3.8% (362/9506) upon retesting. After the second-step screening, a total of 537 newborns were lost to follow-up. The genetic screening found that about 2.29% (230/10,043) individuals carried one or more recessive risk alleles or the mitochondrial mutation. Among them, 18 babies had the pathogenic mitochondrial DNA mutation, 92 babies were SLC26A4 heterozygote carriers, one case with both SLC26A4 and 12S rRNA 1555A>G mutation, 117 babies were GJB2 heterozygote carriers, and two babies were GJB2 homozygote carriers. However, 83.5% (192/230) neonates passed the conventional hearing screening among these carriers.

Conclusions: It might be effective to complement the conventional hearing screening with gene screening for the purpose of early diagnosis and discovery of the late-onset hearing loss.