Title : Assessing and modifying newborn genetic and hearing screening program in Nantong city, China
Background:Hearing loss (HL) is the commonest congenital sensory disorder, affecting 0.3-15.0 per 1,000 infants, with a median of 1.70. Approximately 60% of HL infants have an identifiable genetic etiology. MT-RNR1 variants and some variants of SLC26A4 have been associated with environmental factors and thus regarded as “preventable”. Conventional universal newborn hearing screening (UNHS) may miss some HL and could not identify late-onset HL. Additionally, conventional UNHS could not elucidate the etiology which may indicate meaningful intervention.
Methods:We constructed a population-based cohort study used a 4-stage genetic and hearing screening program at 6 local hospitals in Nantong city, China. Participants were newborn infants born between January 2016 and December 2020 from the Han population. Limited genetic screening for 15 variants in 4 common HL-associated genes and newborn hearing screening (NHS) were offered concurrently to all newborns. Hearing rescreening and/or diagnostic tests were provided for infants with evidence of HL on NHS or genetic variants on screening. Expanded genetic tests for a broader range of genes were targeted to infants with HL with negative results of limited genetic tests.
Results:Among a total of 39 923 infants, 35 920 infants completed the follow-up and were included for analysis. Among the infants included in the analysis, all were from the Han population in China and 52.1% (18 724) were male. The modified genetic and hearing screening program revealed 151 cases of HL and 1454 cases of genetic variation. The limited genetic screening helped identify 33 infants who passed newborn hearing screening, reducing time for diagnosis and intervention; 485 infants with normal hearing with pathogenic SLC26A4 variation and 109 infants with MT-RNR1 variation were at risk for enlarged vestibular aqueduct and aminoglycoside-induced ototoxicity respectively, indicating early aversive or preventive management. Moreover, as of June 2021, the follow-up system identified 11 cases of HL, including 9 cases of genetic variation.
Conclusions:This study found that performing modified genetic and hearing screening in newborns was feasible and provides evidence that the program could identify additional subgroups of infants who need early intervention. These findings suggest an advantage for universal adoption of such a practice.