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Published on: June 8, 2017
Newborn hearing screening and genetic testing in 8974 Brazilian neonates
Karin de A B Nivoloni1, Sueli M da Silva-Costa, Mariza C A Pomílio
1Associação Terapêutica de Estimulação Auditiva e Linguagem-ATEAL, Av Antonio Frederico Ozanan 6561, Jundiai SP 13201-125, Brazil.
Insights
Early diagnosis of congenital hearing loss is crucial. This study integrated genetic testing and otoacoustic emissions screening in newborns, identifying specific mutations linked to hearing impairment for timely intervention.
Area of Science:
- Genetics and Audiology
- Newborn Screening
- Public Health
Background:
- Early diagnosis of hearing loss in newborns is critical for development.
- Current screening methods face challenges in identifying the causes of congenital hearing loss, especially in infants without risk factors.
- Integrating etiological and audiological diagnostics is essential for effective management.
Purpose of the Study:
- To combine etiological and audiological diagnostic approaches for newborns.
- To identify genetic causes of hearing loss in newborns screened via transient otoacoustic emissions (TOAE).
Main Methods:
- Genetic testing for 35delG mutation and MTRNR1 mitochondrial gene mutations (A1555G, A827G) in 8974 newborns.
- Screening of newborns using transient otoacoustic emissions (TOAE).
- Analysis of dried blood spots for genetic mutations.
Main Results:
- 17 newborns failed TOAE screening.
- Four newborns were homozygous for the 35delG mutation, and three had the A827G mutation in the MTRNR1 gene.
- The carrier frequency for the 35delG mutation was 0.94%.
Conclusions:
- The integrated diagnostic approach aids in identifying the etiology of hearing loss.
- Results support public health initiatives by enabling targeted family counseling and early intervention.
- Early etiological diagnosis can potentially reduce long-term rehabilitation costs.
Objective:
An early diagnosis has been a priority in the audiological practice. Identifying hearing loss until 3 months old through Universal Newborn Hearing Screening and intervention before 6 months old, minimize the impact of auditory loss in the health and communication development of these children. However, in the clinical practice, despite the help of the risk indicators in the audiological and etiological diagnosis, the integrated services have come up against the challenge of determining the causes of auditory loss, bearing in mind that approximately 50% of the subjects who have congenital loss do not show risk factors in their clinical history. The current research aims introduce together etiologic and audiological diagnosis of newborns.
Methods:
We eluted dried blood spots from paper and performed genetic testing for 35delG mutation in 8974 newborns that were also screened for transient otoacoustic emissions (TOAE). In addition, the A1555G and A827G mutations in the MTRNR1 mitochondrial gene were screened in all newborns.
Results:
We have found 17 individuals who failed in TOAE. Among them, we detected 4 homozygous newborns for 35delG mutation and 3 individuals with A827G mutation in the MTRNR1 mitochondrial gene. The frequency of 35delG carriers was 0.94% [84/8974]. In all 17 individuals who failed in OAE no other mutation besides those mentioned above was found.
Conclusions:
The results greatly contribute to the public health area indicating the etiologic diagnosis, allowing family counseling as well as the early rehabilitation treatment or surgical intervention. Over time that will help to reduce the costs of rehabilitation considerably.
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