Delays in Infant Hearing Detection and Intervention During the COVID-19 Pandemic: Commentary

Early detection and intervention for congenital hearing loss are critical for speech and language development. Newborns should receive hearing screening, diagnosis, and intervention by 1, 3, and 6 months, respectively. The COVID-19 pandemic has caused delays in each step of this process. Increased out-of-hospital births and shortages of essential health care services likely reduced the proportion of newborns completing screening. Additional factors have contributed to delayed diagnosis. We estimate that up to 50% of infants born with hearing loss in Maryland in 2021 may be delayed in diagnosis. Hearing loss interventions have been affected due to delayed initiation, reduced availability, and lack of in-person services. Delayed diagnosis and treatment of congenital hearing loss are likely to have significant effects on individual patients and public health, the full magnitude of which will not be known for years. Opportunities exist for providers to mitigate the negative effects of COVID-19 on pediatric hearing health care.

Viral and Bacterial Causes of Labyrinthitis

Labyrinthitis is a known inflammation of the membranous structure of the inner ear. Affected patients usually present with nausea and vomiting, vertigo, hearing loss/impairment, and tinnitus. Many etiologies have been proposed to lead to the development of labyrinthitis, including bacterial, viral, systemic, and iatrogenic causes and the most commonly reported causes include viral and bacterial infections. Not many investigations have elaborated on the viral and bacterial etiologies, and the evidence seems to be scattered across the different studies. In the present study, we have reviewed the literature to discuss the current evidence regarding the viral and bacterial causes of labyrinthitis. Many viruses and bacteria were reported in the literature to cause the condition. However, the most common pathogen includes cytomegalovirus and maternal rubella infections, leading to congenital hearing loss. Other viruses as measles and mumps might also lead to developing post-natal labyrinthitis. Studies also indicates that COVID-19 can be a recent cause of the disease. However, evidence regarding this information, similar to the case with other viral and bacterial etiologies, still needs further validation and reporting before making solid conclusions. Accordingly, we encourage researchers to furtherly report about similar cases and conduct epidemiological investigations to better understand the etiology of the disease.

Newborn Hearing Screening: Experience from a Tertiary level Hospital in Nepal

Introduction Congenital hearing loss is one of the commonest causes of hearing impairment and deafness in childhood. Early diagnosis and intervention in time help a child to lead a better life with good language and communication skills. Known risk factors include cytomegalovirus infection and premature birth necessitating a stay in the neonatal intensive care unit. Universal newborn hearing screening has been implemented by many countries due to easy and non-invasive screening test and their ability to identify children who may need early intervention. Methods: All the newborns delivered between December 2018 to November 2020 were screened for congenital hearing loss. The average age at screening was more than 24 hours. Those who were referred in OAE (otoacoustic emissions testing) underwent ABR (auditory brainstem response) test and further workup as needed. Conclusions: The incidence of congenital hearing loss was 1.8 per 1000 live births. This finding is consistent with other previous research. UNHS will be cost-effective easy and feasible method for early detection of hearing loss in newborns. Pediatric health services organizations should prioritize universal newborn hearing screening as a part of the standard of care in birthing services.

Hearing Screening Combined with Target Gene Panel Testing Increased Etiological Diagnostic Yield in Deaf Children

Genetic testing is the gold standard for exploring the etiology of congenital hearing loss. Here, we enrolled 137 Chinese patients with congenital hearing loss to describe the molecular epidemiology by using 127 gene panel testing or 159 variant testing. Sixty-three deaf children received 127 gene panel testing, while seventy-four patients received 159 variant testing. By use of 127 gene panel testing, more mutant genes and variants were identified. The most frequent mutant genes were GJB2, SLC26A4, MYO15A, CDH23, and OTOF. By analyzing the patients who received 127 gene panel testing, we found that 51 deaf children carried variants which were not included in 159 variant testing. Therefore, a large number of patients would be misdiagnosed if only 159 variant testing is used. This study highlights the advantage of 127 gene panel testing, and it suggests that broader genetic testing should be done to identify the genetic etiology of congenital hearing loss.

A novel case of concurrent occurrence of demyelinating-polyneuropathy-causing PMP22 duplication and SOX10 gene mutation producing severe hypertrophic neuropathy

Background Hereditary motor and sensory neuropathy, also referred to as Charcot–Marie–Tooth disease (CMT), is most often caused by a duplication of the peripheral myelin protein 22 (PMP22) gene. This duplication causes CMT type 1A (CMT1A). CMT1A rarely occurs in combination with other hereditary neuromuscular disorders. However, such rare genetic coincidences produce a severe phenotype and have been reported in terms of “double trouble” overlapping syndrome. Waardenburg syndrome (WS) is the most common form of a hereditary syndromic deafness. It is primarily characterized by pigmentation anomalies and classified into four major phenotypes. A mutation in the SRY sex determining region Y-box 10 (SOX10) gene causes WS type 2 or 4 and peripheral demyelinating neuropathy, central dysmyelinating leukodystrophy, WS, and Hirschsprung disease. We describe a 11-year-old boy with extreme hypertrophic neuropathy because of a combination of CMT1A and WS type 2. This is the first published case on the co-occurrence of CMT1A and WS type 2. Case presentation The 11-year-old boy presented with motor developmental delay and a deterioration in unstable walking at 6 years of age. In addition, he had congenital hearing loss and heterochromia iridis. The neurological examination revealed weakness in the distal limbs with pes cavus. He was diagnosed with CMT1A by the fluorescence in situ hybridization method. His paternal pedigree had a history of CMT1A. However, no family member had congenital hearing loss. His clinical manifestation was apparently severe than those of his relatives with CMT1A. In addition, a whole-body magnetic resonance neurography revealed an extreme enlargement of his systemic cranial and spinal nerves. Subsequently, a genetic analysis revealed a heterozygous frameshift mutation c.876delT (p.F292Lfs*19) in the SOX10 gene. He was eventually diagnosed with WS type 2. Conclusions We described a patient with a genetically confirmed overlapping diagnoses of CMT1A and WS type 2. The double trouble with the genes created a significant impact on the peripheral nerves system. Severe phenotype in the proband can be attributed to the cumulative effect of mutations in both PMP22 and SOX10 genes, responsible for demyelinating neuropathy.