[Study of newborn hearing and genetic screening in Jinan].

Objective: In this study, we employed newborn hearing screening and gene screening concurrently to explore the hearing loss associated with mutations in the city of Jinan.

Methods: A total of 3 288 newborns born between March 2013 and December 2013 in Jinan Maternity and Child Care Hospital received hearing concurrent genetic screening. Transiently evoked otoacoustic emissions (TEOAE) was used in rooming-in newborns, while TEOAE and auto auditory brainstem response (AABR) was used in infants in neonatal intensive care unit (NICU). Two drops of heel blood were harvested with filter paper. Nine mutations [GJB2 (235delC, 35delG, 299delAT, 176del16), SLC26A4 (IVS7-2A>G,2168 A>G), GJB3 (538 C>T), 12SrRNA (1555 A>G, 1494C>T)] of 4 frequent genes associated with Chinese hearing loss were determined by gene chip in these dried blood samples.

Results: Among 3 288 newborns, 363 cases failed to pass the hearing screening, and 36 cases of these 363 newborns carried mutations, with a carrier rate of 9.91%. 2 925 cases passed the hearing screening, of which 113 carried mutations, with a carrier rate of 3.86%. There was a significantly statistic difference (χ2=8.67, P=0.000) in carrier rate between two groups. 149 (4.53%) infants were detected to carry at least one mutation allele,among which 113 cases passed the hearing screening and 36 cases failed. Seven cases were diagnosed to have hearing loss. Homozygous GJB2 mutation was detected in 2 cases, compound heterozygous GJB2 mutation was detected in 1 case, and heterozygous GJB2 mutation in 88 cases. There were 91 cases carried GJB2 mutations totally, with a total rate of 2.76%. There were 40 cases were detected to carry heterozygous SLC26A4 mutation, with a carrier rate of 1.22%. Nine cases had heterozygous GJB3 mutation, with a carrier rate of 0.27%. Six cases had homogeneous mitochondria 12SrRNA mutation, and 1 had heterogeneous mutations. There were 7 cases totally, with a total rate of 0.21%. 142 infants with gene mutation should be follow-up.

Conclusion: A follow-up system in infants, passed hearing screening,with single heterozygous mutation and mutations associated with drug-induced hearing loss, can help to detect infants with hearing defects early and effectively prevent late-onset hearing impairment.