• Clinical and Experimental Pediatrics
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• v.49 no.10
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• pp.1056-1060
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• 2006

Purpose : As hearing ability affects language and cognitive development, early detection and intervention of congenital hearing defects is very important. We analyzed the result of newborn hearing screening using automated auditory brainstem response and estimated the incidence of congenital hearing defects in newborn infants in Korea. Methods : Hearing screening tests were done on 7,218 newborn infants who were delivered at Cheil General Hospital from July 1, 2004 to June 30, 2005. The first screening test was done on the second day of life with automated auditory brainstem response(AABR) using $ALGO{\bigcirc}^{(3)}$ Newborn hearing screener($Natus^{(R)}$ Medical Incorporated, San Carlos, USA) with 35 dB sound level. The newborn infants who did not pass the initial screening test took the second screening AABR test before discharge from the nursery. Infants who did not pass these screenings at the nursery were followed up at the Department of Otorhinolaryngology, Samsung Seoul Hospital. Results : Total 7,218 infants(83.3 percent of total 8,664 live births of the Cheil General Hospital) were screened in the nursery, and 55 of them failed to pass the newborn screening. Among 55 infants who were referred, six were lost during follow-up, and 14 were confirmed as hearing impaired. Six of them(42.8 percent) do not have any risk factors for hearing impairment. We can estimate that the incidence of hearing defects is about 1.9-2.8 per 1,000 live births. Conclusion : Automated auditory brainstem response is an effective tool to screen the hearing of newborn infants. Congenital hearing loss is more frequent than metabolic diseases on which screening tests are available in the newborn period. About 40 percent of infants who have hearing defects do not have any risk factors for hearing impairment. Therefore, universal newborn hearing screening must be recommended to all neonates.

• Journal of agricultural medicine and community health
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• v.43 no.3
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• pp.172-179
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• 2018

Objectives: To review the status of newborn hearing screening (NHS) and to investigate the effect of the examiners on NHS tests to help the quality control of NHS at a general hospital in a city. Methods: The charts of newborns from January 2015 to March 2016 and from August 2016 to October 2017 were retrospectively reviewed. We compared the results of tests performed by several examiners(group 1) with those performed by one audiologist (group 2) using the same automated auditory brainstem response test. Results: The screening rate and referral rate were not significantly different between group 1 and group 2. The confirmatory test rate was higher in the group 2, but it was not significant. In group 1, the number of tests performed 3 or more times in one ear at one time was significantly higher. The number of tests performed in only one ear at one time was higher in group 2. The screening rate within one month after birth was 64.21%, referral rate was 7.32%, confirmatory test rate within 3 months after birth was 21.74%, and the prevalence of hearing loss was 1.46%. Conclusions: There was no significant difference of results depending on the examiners. In order to make proper screening test, it is necessary to periodically educate the examiner and to instruct the examiner by the supervisor doctors.

• Korean Journal of Clinical Laboratory Science
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• v.39 no.2
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• pp.113-121
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• 2007

Hearing loss is a common congenital disorder that is frequently associated with mutations in the Cx26 gene (GJB2). Recently, the mutation analysis of GJB2 has been used in a newborn screening test for the detection of hearing impairment. Population-based studies should be performed before the application of genetic testing for the identification of deaf newborns. In this study, 8 positions of GJB2 mutations-including 35delG, 167delT, 235delC, V27I, V37I, M34T, E114G, and I203T-were analyzed using PCR-direct sequencing in a total of 437 healthy Korean neonates. DNAs from dried blood spots were extracted using a commercial DNA extraction kit. The PCR-amplified products (783 bps) of the GJB2 gene were detected using 2% agarose gel electrophoresis and subjected to direct sequencing. The sequences were compared with those in the GenBank database by using the BLAST program. In this study, 5 GJB2 mutations -including V27I (79G>A), V37I (109G>A), E114G (341A>G), I203T (608T>C), and 235delC- were found. Of the 437 neonate samples, 301 subjects showed GJB2 mutations (68.9%, 301/437). The V27I mutation was found in 271 subjects and was the most frequent (62.0%, 271/437). The E114G, I203T and V37I mutations were shown in 146, 17 and 14 subjects, respectively. The 235delC mutation was found in 1 subject. The E114G mutation was frequently accompanied by the V27I mutation. V27I/E114G (97.2%, 143/147) was the most common double mutation and 3 subjects had the double mutation V27I/I203T. A triple mutation, V27I/E114G/I203T, was found in 1 subject. In conclusion, PCR-direct sequencing is a convenient tool for the rapid detection of GJB2 mutations and this data might provide information for the genetic counseling of the GJB2 gene.

• Neonatal Medicine
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• v.16 no.2
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• pp.213-220
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• 2009

Purpose: Hearing loss is one of the common birth defects in humans, with a reported prevalence of 1-3 per 1000 newborns. We investigated the incidence of hearing loss and evaluated the use of neonatal hearing screening test in neonatal intensive care unit (NICU) graduates who are at greater risk for hearing loss than normal newborns. Methods: The neonates admitted to the NICU of Asan Medical Center from 1 March, 2003 to 30 March, 2008 who were available for follow-up were included. Those who failed the first auditory brainstem response prior to discharge were retested with the stapedial reflex test, auditory brainstem response and tympanometry in the Otolaryngology department. Results: Of 2,137 neonates, 2,000 (93.5%) neonates were tested prior to discharge. Sixty-seven neonates (3.4%) failed the first newborn hearing screening test. Of 67 infants, 52 infants were retested for a second hearing test. Excluding 10 infants (19.2%) who were lost during follow-up, 16 infants were confirmed to have hearing impairment of which 12 and 4 infants had unilateral and bilateral hearing loss, respectively. Of 16 infants, 5 did not meet the criteria set by the Korean National Health Insurance Corporation. Conclusion: The prevalence of hearing impairment in NICU graduates is about 0.8%, excluding those who were lost for follow up, necessitating a systemic and effective hearing assessment program among these high risk infants and more generous national insurance coverage.

• Clinical and Experimental Pediatrics
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• v.52 no.3
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• pp.289-294
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• 2009

Purpose : To assess the usefulness of magnetic resonance imaging (MRI), karyotyping, brainstem auditory evoked potential (BAEP), electroencephalogram (EEG), tandem mass screening test, and newborn metabolic screening test in children with language delay for diagnosing underlying diseases. Methods : From January 2000 to June 2007, a retrospective chart review was performed for 122 children with language delay who visited the Child Neurology Clinic at Yeungnam University Hospital and who underwent neuropsychologic tests and other diagnostic evaluations for underlying diseases. They were grouped into phenomenological diagnostic categories, and test results were analyzed according to the underlying diseases. Results : Of 122 patients, 47 (38.5%) had mental retardation, 40 (32.8%) had developmental language disorders, 23 (18.9 %) had borderline IQ, and 12 (9.8%) had autism spectrum disorder. In 26 (21.3%) cases, the causes or relevant clinical findings to explain language delay were found. Eight (10.4%) of 77 MRIs, 6 (8.0%) of 75 EEGs, and 4 (5%) of 80 BAEPs showed abnormal results. Results directly attributed to diagnosing underlying diseases were 2 hearing defects in BAEPs and 1 bilateral perisylvian cortical dysplasia in MRIs. No abnormal results were found in karyotyping, tandem mass screening tests, and new-born screening tests. Conclusion : Commonly used tests to diagnose the cause of language delay are not very effective and should only be used selectively, according to patient characteristics. However, despite the low diagnostic yields from these tests, because many patients show abnormal results, these tests are useful when conducted in complete evaluation.