Congenital Cytomegalovirus Testing Outcomes From the ValEAR Trial

OBJECTIVE

To determine the positivity rate of congenital cytomegalovirus (cCMV) testing among universal, hearing-targeted CMV testing (HT-cCMV) and delayed targeted dried blood spot (DBS) testing newborn screening programs, and to examine the characteristics of successful HT-cCMV testing programs.

STUDY DESIGN

Prospective survey of birth hospitals performing early CMV testing.

SETTING

Multiple institutions.

METHODS

Birth hospitals participating in the National Institutes of Health ValEAR clinical trial were surveyed to determine the rates of cCMV positivity associated with 3 different testing approaches: universal testing, HT-cCMV, and DBS testing. A mixed methods model was created to determine associations between successful HT-cCMV screening and specific screening protocols.

RESULTS

Eighty-two birth hospitals were surveyed from February 2019 to December 2021. Seven thousand six hundred seventy infants underwent universal screening, 9017 infants HT-cCMV and 535 infants delayed DBS testing. The rates of cCMV positivity were 0.5%, 1.5%, and 7.3%, respectively. The positivity rate for universal CMV screening was less during the COVID-19 pandemic than that reported prior to the pandemic. There were no statistically significant drops in positivity for any approach during the pandemic. For HT-cCMV testing, unique order sets and rigorous posttesting protocols were associated with successful screening programs.

CONCLUSION

Rates of cCMV positivity differed among the 3 approaches. The rates are comparable to cohort studies reported in the literature. Universal CMV prevalence decreased during the pandemic but not significantly. Institutions with specific order set for CMV testing where the primary care physician orders the test and the nurse facilitates the testing process exhibited higher rates of HT-cCMV testing.

Association of Diet Patterns and Post-Operative Tympanostomy Tube Otorrhea: A Pilot Study

OBJECTIVE

The objective of this study was to explore diet patterns in children with tympanostomy tube placement (TTP) complicated by postoperative tympanostomy tube otorrhea.

STUDY DESIGN

Cross-sectional survey and retrospective cohort study.

METHODS

Caregivers of children (0-12 years old), at a tertiary-care pediatric hospital who underwent TTP within 6 months to 2 years prior to enrollment were included. Children with a history of Down syndrome, cleft palate, craniofacial syndromes, known immunodeficiency, or a non-English-speaking family were excluded. Our primary outcome variable was the number of otorrhea episodes. The primary predictor was diet patterns, particularly dessert intake, which was captured through a short food questionnaire.

RESULTS

A total of 286 participants were included in this study. The median age was 1.8 years (IQR, 1.3, 2.9). A total of 174 (61%) participants reported at least one episode of otorrhea. Children who consumed dessert at least two times per week had a higher risk of otorrhea compared to children who consumed one time per week or less (odds ratio [OR], 3.22, 95% Confidence Interval [CI]: 1.69, 6.12). The odds ratio increase continued when considering more stringent criteria for otorrhea (multiple episodes or one episode occurring 4 weeks after surgery), with a 2.33 (95% CI: 1.24, 4.39) higher odds of otorrhea in children with dessert intake at least 2 times per week.

CONCLUSIONS

Our pilot data suggest that episodes of otorrhea among children with TTP were associated with more frequent dessert intake. Future studies using prospectively administered diet questionnaires are necessary to confirm these findings.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:3575-3581, 2023.

Comprehensive Gene Panel Testing for Hearing Loss in Children: Understanding Factors Influencing Diagnostic Yield

OBJECTIVE

To evaluate factors influencing the diagnostic yield of comprehensive gene panel testing (CGPT) for hearing loss (HL) in children and to understand the characteristics of undiagnosed probands.

STUDY DESIGN

This was a retrospective cohort study of 474 probands with childhood-onset HL who underwent CGPT between 2016 and 2020 at a single center. Main outcomes and measures included the association between clinical variables and diagnostic yield and the genetic and clinical characteristics of undiagnosed probands.

RESULTS

The overall diagnostic yield was 44% (209/474) with causative variants involving 41 genes. While the diagnostic yield was high in the probands with congenital, bilateral, and severe HL, it was low in those with unilateral, noncongenital, or mild HL; cochlear nerve deficiency; preterm birth; neonatal intensive care unit admittance; certain ancestry; and developmental delay. Follow-up studies on 49 probands with initially inconclusive CGPT results changed the diagnostic status to likely positive or negative outcomes in 39 of them (80%). Reflex to exome sequencing on 128 undiagnosed probands by CGPT revealed diagnostic findings in 8 individuals, 5 of whom had developmental delays. The remaining 255 probands were undiagnosed, with 173 (173/255) having only a single variant in the gene(s) associated with autosomal recessive HL and 28% (48/173) having a matched phenotype.

CONCLUSION

CGPT efficiently identifies the genetic etiologies of HL in children. CGPT-undiagnosed probands may benefit from follow-up studies or expanded testing.

Perspective on the Development of a Large-Scale Clinical Data Repository for Pediatric Hearing Research

The use of "big data" for pediatric hearing research requires new approaches to both data collection and research methods. The widespread deployment of electronic health record systems creates new opportunities and corresponding challenges in the secondary use of large volumes of audiological and medical data. Opportunities include cost-effective hypothesis generation, rapid cohort expansion for rare conditions, and observational studies based on sample sizes in the thousands to tens of thousands. Challenges include finding and forming appropriately skilled teams, access to data, data quality assessment, and engagement with a research community new to big data. The authors share their experience and perspective on the work required to build and validate a pediatric hearing research database that integrates clinical data for over 185,000 patients from the electronic health record systems of three major academic medical centers.

Infectious complications and ventilation tubes in pediatric cochlear implant recipients

OBJECTIVES/HYPOTHESIS

At many centers, ventilating tubes (VTs) are placed routinely in otitis-prone pediatric cochlear implant recipients. However, this practice is controversial, as many otologists believe VTs represent a possible route for contamination of the device. Toward better understanding of the safety of VTs, we reviewed our center's infectious complications and their relationship to the presence of tubes.

STUDY DESIGN

Retrospective cohort study.

METHODS

All patients undergoing cochlear implantation at our institution between 1990 and 2012 were reviewed for complications and their association with the presence of VTs.

RESULTS

A total of 478 patients (557 ears) were reviewed, representing over 2,978 patient-years of follow-up. In 135 ears (24.2%), a VT was present at time of, or placed at some point after, implantation. The remainder either never had a VT or it had extruded prior to implantation. Overall, 63 complications occurred, of which 17 were infectious. The most common were cellulitis (four), device infection (five), and meningitis (four). Only one occurred while a tube was present, and was a device infection in an ear having a retained VT in place for almost 4 years. No difference was observed in overall rates of infectious complications between the group with VTs and those who never had VTs.

CONCLUSIONS

This series, the largest to date, indicates that infectious complications after cochlear implantation are rarely associated with the presence of VTs, supporting the concept that, overall, VTs are safe in cochlear implant recipients. Close monitoring is essential, including prompt removal of tubes when they are no longer needed.

LEVEL OF EVIDENCE

4. Laryngoscope, 126:1671-1676, 2016.

Isolation of a novel latent transforming growth factor-beta binding protein gene (LTBP-3)

This paper reports the molecular cloning of a novel gene in the mouse that shows structural similarities to the microfibril protein fibrillin and to the latent transforming growth factor-beta (TGF-beta) binding protein (LTBP), a component of the latent TGF-beta complex. The gene was initially isolated during a low stringency polymerase chain reaction screen of a NIH 3T3 cell cDNA library using primers that amplify a human fibrillin-1 epidermal growth factor-like repeat. Three lines of evidence suggest that the mouse gene is a third member of the LTBP gene family, which we designate LTBP-3. First, the deduced polypeptide, which consists of 15 epidermal growth factor-like repeats, 3 TGF binding protein repeats, and 2 proline- and glycine-rich sequences, shows 38.4% identity with LTBP-1 but only 27% identity with fibrillin-1. Second, the gene appears to be co-expressed in developing mouse tissues with TGF-beta. Third, immunoprecipitation studies using mouse preosteoblast MC3T3-E1 cells and a specific anti-peptide polyclonal antiserum reveal that the mouse polypeptide forms a complex with the TGF-beta 1 precursor. Finally, we note that the LTBP-3 gene was recently localized to a distinct genetic locus (Li, X., Yin, W., Perez-Jurado, L., Bonadio, J., and Francke, U. (1995) Mamm. Genome 6, 42-45). Identification of a third binding protein provides further insight into a mechanism by which latent TGF-beta complexes can be targeted to connective tissue matrices and cells.

Primary structure and developmental expression of Fbn-1, the mouse fibrillin gene

Previous studies have reported > 10 kilobases of human fibrillin-1 cDNA sequence, but a consensus regarding the 5' end of the transcript remains to be worked out. One approach to developing a clear consensus would be to search for regions of evolutionary conservation in transcripts from a related species such as mouse. As reported here, the mouse fibrillin-1 transcript encodes a highly conserved polypeptide of 2,871 amino acids. The upstream sequence that flanks the ATG is considerably less well conserved, however. Indeed, the ATG codon (which occurs in the context of a Kozak consensus sequence and is located just upstream of a consensus signal peptide) signals the point where human and mouse fibrillin-1 sequences cease to be nearly identical. Together, these results are consistent with previous efforts by Pereira et al. (Pereira, L., D'Alessio, M., Ramirez, F., Lynch, J. R., Sykes, B., Pangilinan, T., and Bonadio, J. (1993) Human Mol. Genet. 2, 961-968) to identify the human fibrillin-1 translational start site. Sequences immediately upstream of the ATG are GC-rich and devoid of TATA and CCAAT boxes, which suggests that the mouse fibrillin-1 gene will be broadly expressed. A survey of expression in mouse embryo tissues is consistent with this hypothesis and suggests two novel functions for fibrillin-associated microfibrils in non-elastic connective tissues.

Structure, chromosomal localization, and expression pattern of the murine Magp gene

The microfibril-associated glycoprotein (MAGP) was recently established as a discrete constituent of 10-nm microfibrils. We have characterized the primary structure of the mouse transcript, the structure and chromosomal localization of the murine gene, and the developmental pattern of gene expression. The transcript consists of 1,037 base pairs as determined by cDNA cloning, Northern blot analysis, S1 nuclease mapping, and primer extension mapping. Using a cDNA fragment as a probe, we isolated a single genomic clone that contained the entire mouse gene. Analysis of this clone indicated that Magp is fragmented into 9 exons, with the initiator Met codon located in exon 2. As determined by analysis of somatic cell hybrid lines and by fluorescence in situ hybridization, the mouse gene was mapped to chromosome 4 at a location corresponding to region D3-E1. Genomic sequence immediately upstream of the transcription start site was found to be GC-rich but lacked TATA or CCAAT boxes as well as other cis-acting motifs known to regulate transcription. Promoters of this type are usually found in genes that exhibit broad temporal and spatial patterns of expression. Consistent with this idea, the Magp transcript appeared to be the widespread product of mesenchymal/connective tissue cells throughout mouse development. This study presents the first comprehensive evaluation of microfibril gene expression during mammalian development.