Identification of Potential Clusters of Signs and Symptoms to Prioritize Patients' Eligibility for AADCd Screening by 3-OMD Testing: An Italian Delphi Consensus.

Introduction: AADCd is an ultrarare, underdiagnosed neurometabolic disorder for which a screening test (3-OMD dosing on dried blood spot (DBS)) and targeted gene therapy (authorized in the EU and the UK) are available. Therefore, it is mandatory to raise awareness of presenting symptoms and signs among practitioners. Delivering scientifically sound information to promote screening of patients with the correct cluster of symptoms and signs would be critical. Materials and Methods: In light of the lack of sound evidence on this issue, expert opinion level of evidence was elicited with the Delphi method. Fourteen steering committee members invited a panel of 29 Italian experts to express their opinions on a series of crucial but controversial topics related to using 3-OMD DBS as a screening method in AADCd. Clusters of symptoms and signs were divided into typical or atypical, depending on age groups. Inclusion in newborn screening programs and the usefulness of a clinical score were investigated. A five-point Likert scale was used to rate the level of priority attributed to each statement. Results: The following statements reached the highest priority: testing pediatric patients with hypotonia, developmental delay, movement disorders, and oculogyric crises; inclusion of 3-OMD dosing on DBS in neonatal screening programs; development of a clinical score to support patients' selection for 3-OMD screening; among atypical phenotypes based on clinical characteristics of Italian patients: testing patients with intellectual disability and parkinsonism-dystonia. Discussion. Clusters of symptoms and signs can be used to prioritize testing with 3-OMD DBS. A clinical score was rated as highly relevant for the patient's selection. The inclusion of 3-OMD dosing in newborn screening programs was advocated with high clinical priority.

How Can Newborn Toxicology Testing Be More Equitable? An Interactive Ethics Workshop.

Introduction: Practice variation in newborn toxicology testing during the birth hospitalization exists across institutions and legal jurisdictions. While testing can provide benefits, indiscriminate testing has been shown to perpetuate health care inequities. In the backdrop of an opioid epidemic and a charged medicolegal landscape, this workshop guides participants to reexamine newborn toxicology testing through a shared ethical lens. Methods: We conducted a live, 90-minute workshop in English at an international pediatric conference. Physicians, residents, and fellows participated in large- and small-group breakout sessions to learn relevant clinical and bioethical frameworks, share their own local context and expertise, and explore ethical applications through case-based discussions. We administered two anonymous online follow-up surveys to assess self-perceived impact on participant knowledge, behavior, and clinical practice. Results: Seven facilitators and 45 individuals participated in the workshop. Eighteen participants completed survey 1 immediately following workshop conclusion, and six participants completed survey 2 after 3 months had elapsed. Immediately following the workshop, 94% of respondents reported that they had been introduced to a new idea, and 82% were considering practice change. A low response rate to survey 2 limited interpretation, but some respondents reported self-perceived change following workshop attendance. Discussion: This workshop facilitated conversation between physician participants on a complex pediatric health care inequity issue using an ethical framework.

Phenylketonuria - newborn screening as a health protection in society.

OBJECTIVE: Aim: Phenylketonuria is the most prevalent inherited metabolic disorder. Early detection and prompt treatment can prevent serious neurological consequences. This has become possible thanks to the implementation of newborn screening programmes. The objective of this review is to provide readers with a comprehensive understanding of the phenylketonuria and the role that neonatal screening plays in the protection of public health. PATIENTS AND METHODS: Materials and Methods: A review of the literature was conducted using the PubMed database, with the search period encompassing the most recently published scientific sources. Analysis of the literature. This article presents phenylketonuria as an example of an inherited metabolic disorder, outlines the treatment options, and discusses the potential implications of hyperphenylalaninemia. Furthermore, it also delineates the various aspects of health that are influenced by newborn screening. CONCLUSION: Conclusions: Phenylketonuria represents a significant health problem in the population. The development of screening tests has transformed healthcare, including improvements in quality of life, prognosis, and reductions in the number of comorbidities in patients. It is essential to disseminate knowledge among the society about the importance of newborn screening tests in order to enhance awareness and prevent refusal to participate.

Mapping neonatal hearing screening services in Cape Town metro: A situational analysis.

BACKGROUND:  Childhood hearing loss is a global health concern. Despite the proven benefits of neonatal hearing screening (NHS), it is not yet mandated in South Africa. The lack of awareness of hearing loss and absence of NHS leads to delayed diagnosis and adverse developmental outcomes for affected children. AIM:  The study aimed to assess the availability of NHS services across primary healthcare (PHC) facilities in the City of Cape Town (CCT). SETTING:  Surveys were conducted with 26 PHC facilities in the CCT metropolitan areas that offer mother and child healthcare services. METHODS:  Surveys gathered data through online and telephone methods. The surveys aimed to assess the availability and nature of NHS services, care pathways and training of healthcare professionals regarding NHS. RESULTS:  None of the facilities used objective screening methods to screen hearing or have standardised care pathways for at-risk babies. Instead, they relied on parental concerns, with the use of the Road to Health book. None of the respondents reported having received hearing screening training, and the majority of participants (62%) lacked confidence in their knowledge of ear and hearing care. CONCLUSION:  The absence of NHS services highlights the need for standardised protocols and increased awareness among healthcare workers and caregivers. Implementing NHS services could facilitate earlier diagnosis and intervention of hearing loss for infants in the Western Cape.Contribution: This study's findings could guide efforts to improving access to NHS access at PHC level in Cape Town, ultimately providing early hearing screening services to infants.

Risk factors and hearing outcomes in infants and young children in KwaZulu-Natal, South Africa.

BACKGROUND:  Targeted new-born hearing screening, based on high risk factors is recommended in the absence of universal new-born hearing screening in resource-constrained settings. The relevance of risk factors listed in the guidelines of high-income countries and used by low-middle income countries remains relatively unknown. Risk factors consistent with the epidemiological profile, evolution of risks and disease burden in these countries need to be considered. OBJECTIVES:  This study aimed to profile the frequency of risk factors and their manifestation in hearing outcomes of young children in the KwaZulu-Natal province of South Africa. METHOD:  A chart review of N = 1433 patients' archival audiology records was conducted, conveniently sampled from a single tertiary hospital (n = 351), a provincial assessment and therapy centre (n = 649), a university clinic (n = 291), and two schools for the deaf (n = 142). RESULTS:  Overall, 56% of the participants presented with either a conductive, sensorineural or a mixed hearing loss; 62% of the children had between 1 and 2 risk factors present (Mean [M] = 1.1; standard deviation [s.d.] = 0.98). Admission to neonatal intensive care unit, maternal infections, bacterial and viral infections and chemotherapy, from the Joint Committee on Infant Hearing list of high risk factors were significantly associated with hearing loss (p  0.05). Known non-JCIH risks, emerging risks and other statistically significant contextually relevant risk factors were also noted. CONCLUSION:  Understanding the profile of high risk factors in a given context has implications for prevention, early hearing identification and intervention services.Contribution: Targeted new-born hearing screening needs to be based on risk factors that are contextually relevant. This study is one of the first profiling high risk factors for hearing loss in children in KZN, the province with the second highest population in South Africa.

Newborn hearing screening in Eastern Saudi Arabia: A tertiary hospital experience.

OBJECTIVES: To analyze the performance of a leading institution in implementing newborn hearing screening and address two key areas: the knowledge gap in screening practice and the prevalence of permanent sensorineural hearing loss in Saudi Arabia. METHODS: We analyzed the prevalence of hearing impairment in all live births at King Fahad Hospital of the University, Al Khobar, Saudi Arabia, from September 2018 to June 2022. Automated auditory brainstem response was used for both initial screening and rescreening. Newborns who failed the rescreening underwent a diagnostic evaluation. We assessed the coverage of initial screening, the rate of lost follow-up, referrals for rescreening and diagnostic evaluation, and the prevalence of hearing impairment. RESULTS: A total of 5,986 newborns were born. Of these, 96.5% were screened. The passing rate for the initial screening and rescreening was 71.8%. However, 27.5% of newborns were lost to follow-up. Only 0.7% required referral for a diagnostic evaluation. The overall prevalence of hearing impairment was 2.6 per 1,000 newborns. CONCLUSION: Early identification of hearing loss through newborn screening improves the lives of affected individuals. Our program currently meets the World Health Organization's 1-3-6 benchmark goals. However, the underestimation of permanent hearing loss due to the 30% lost-to-follow-up rate is a limitation. Emphasizing the importance of the screening program is crucial to raising awareness and improving the accuracy of prevalence rates.

Sustainability of newborn screening for sickle cell disease in resource-poor countries: A systematic review.

Sickle cell disease (SCD) is a worldwide genetic blood disorder. Roughly 400,000 babies are born with SCD each year worldwide. More than 75% of these births occur in sub-Saharan Africa. The establishment of sustainable newborn screening NBS programs is an excellent approach to improving the health of persons living with SCD. The need to set up such programs in Africa cannot be overemphasized. However, initial implementation does not guarantee sustainability. More than 500 children with sickle cell anaemia (SCA) die every day due to lack of access to early diagnosis and related treatment. We systematically highlighted suggestions proffered so far, for the sustainability of NBS in low income, high burden countries. We searched online databases, PubMed, and Google Scholar for literature on sustainability of newborn screening (NBS) published between 2012 and 2022. Articles were included if they reported as outcome; sustainability, government participation, scaling up and expansion of NBS, improved patient enrolment in the newborn screening programe. Articles not suggesting same were excluded. Data were extracted from published reports. Primary outcome was government participation and enhanced patient enrolment in the NBS programe. Thematic content analysis was applied using inductive and deductive codes. We came up with 9 major themes. This study is registered with PROSPERO with registration number as CRD42023381821. Literature search yielded 918 articles (including manual searching). After screening, nine (9) publications were suitable for data extraction and analysis. Two more articles were added by manual searching, making a total of eleven (11) articles. The most frequently addressed core elements of sustainability in these papers were complete integration of services into national health care systems for sustainability of NBS programs in Low-income high-burden countries, funding and engagement from government partners from the very beginning of program development should be prioritized. Screening should be tailored to the local context; using DBS on HemoTypeSC could be a game changer for scaling up and expanding the newborn screening program in Sub-Saharan Africa.

Incorporating Next-Generation Sequencing as a Second-Tier Test for Primary Carnitine Deficiency.

BACKGROUND: Newborn screening (NBS) for primary carnitine deficiency (PCD) has poor performance. This study aimed to evaluate the feasibility of incorporating next-generation sequencing (NGS) as a second-tier PCD test. METHODS: Between March and December 2020, 60,070 newborns were screened for inherited metabolic disorders. Newborns with free carnitine (C0) levels below 8.5 µmol/L were selected for second-tier genetic testing. RESULTS: In total, 130 (0.22%) newborns with low C0 levels underwent second-tier genetic testing, 87 (66.92%) had positive genetic testing results, and 30 (23.08%) carried pathogenic variants of the SLC22A5 gene. Six newborns were diagnosed with PCD. The incidence of PCD was approximately 1 in 1:10,012 newborns. The PPV reached 20% after combining with second-tier NGS. Of the eight variants identified in patients with PCD, the three most common variants were c.760C>T (p.Arg254*), c.51C>G (p.Phe17Leu), and c.1400C>G (p.Ser467Cys). The C0 levels of patients with PCD were significantly lower than those of PCD carriers (p = 0.0026) and PCD-negative individuals (p = 0.0005). CONCLUSIONS: Our results showed that the PPV reached 20% after combining with second-tier NGS. The MS/MS-based NBS and second-tier NGS combination can effectively reduce the false-positive rate and detect PCD in patients.

Improving growth in infants with CF.

Cystic fibrosis (CF) results in chronic pulmonary infections, inflammation, pancreatic insufficiency, and multiple gastrointestinal manifestations. Malnutrition and poor growth are hallmarks of CF, and strongly associated with poor outcomes. Through newborn screening, many infants can be diagnosed within a few days of life, which allows for early initiation of nutritional counseling and close clinical follow-up. Obstacles to growth for infants with CF start in utero, as newborns with CF can have a lower birth weight than the general population. Improving infant growth has been linked to improved clinical outcomes and survival. It remains a top priority and challenge for caregivers and healthcare teams. An interdisciplinary approach, including registered dietitian and social work support, is essential to optimize health for infants with CF. Remaining barriers to normalcy include deficits in linear growth, lack of accurate nutrition biomarkers, persistence of inequities related to social determinant of health, particularly in the global CF community.

Prediction models for retinopathy of prematurity occurrence based on artificial neural network.

INTRODUCTION: Early prediction and timely treatment are essential for minimizing the risk of visual loss or blindness of retinopathy of prematurity, emphasizing the importance of ROP screening in clinical routine. OBJECTIVE: To establish predictive models for ROP occurrence based on the risk factors using artificial neural network. METHODS: A cohort of 591 infants was recruited in this retrospective study. The association between ROP and perinatal factors was analyzed by univariate analysis and multivariable logistic regression. We developed predictive models for ROP screening using back propagation neural network, which was further optimized by applying genetic algorithm method. To assess the predictive performance of the models, the areas under the curve, sensitivity, specificity, negative predictive value, positive predictive value and accuracy were used to show the performances of the prediction models. RESULTS: ROP of any stage was found in 193 (32.7%) infants. Twelve risk factors of ROP were selected. Based on these factors, predictive models were built using BP neural network and genetic algorithm-back propagation (GA-BP) neural network. The areas under the curve for prediction models were 0.857, and 0.908 in test, respectively. CONCLUSIONS: We developed predictive models for ROP using artificial neural network. GA-BP neural network exhibited superior predictive ability for ROP when dealing with its non-linear clinical data.

Cystic fibrosis.

Cystic fibrosis is a rare genetic disease caused by mutations in CFTR, the gene encoding cystic fibrosis transmembrane conductance regulator (CFTR). The discovery of CFTR in 1989 has enabled the unravelling of disease mechanisms and, more recently, the development of CFTR-directed therapeutics that target the underlying molecular defect. The CFTR protein functions as an ion channel that is crucial for correct ion and fluid transport across epithelial cells lining the airways and other organs. Consequently, CFTR dysfunction causes a complex multi-organ disease but, to date, most of the morbidity and mortality in people with cystic fibrosis is due to muco-obstructive lung disease. Cystic fibrosis care has long been limited to treating symptoms using nutritional support, airway clearance techniques and antibiotics to suppress airway infection. The widespread implementation of newborn screening for cystic fibrosis and the introduction of a highly effective triple combination CFTR modulator therapy that has unprecedented clinical benefits in up to 90% of genetically eligible people with cystic fibrosis has fundamentally changed the therapeutic landscape and improved prognosis. However, people with cystic fibrosis who are not eligible based on their CFTR genotype or who live in countries where they do not have access to this breakthrough therapy remain with a high unmet medical need.

Cost-effectiveness of portable-automated ABR for universal neonatal hearing screening in India.

The World Health Organization considers Universal Neonatal Hearing Screening (UNHS) essential to global public health. Rashtriya Bal Swasthya Karyakram has included newborn hearing screening in India since 2013. The program faces human, infrastructure, and equipment shortages. First-line hearing screening with improved diagnostic accuracy is needed. The Portable Automated Auditory Brainstem Responses (P-AABR) can be used in remote areas for UNHS due to its low infrastructure needs and diagnostic accuracy. This study evaluated the cost-effectiveness of P-AABR in UNHS. We employed an analytical model based on decision trees to assess the cost-effectiveness of Otoacoustic Emission (OAE) and P-AABR. The total cost to the health system for P-AABR, regardless of true positive cases, is INR 10,535,915, while OAE costs INR 7,256,198. P-AABR detects 262 cases, whereas OAE detects 26 cases. Portable Automated ABR costs INR 97 per case detection, while OAE costs INR 67. The final ICER was 97407.69. The P-AABR device is cost-effective, safe and feasible for UNHS Rashtriya Bal Swasthya Karyakram (RBSK) programs. Beyond reducing false referrals and parent indirect costs, it detects more hearing-impaired infants. Even in shortages of skilled workers, existing staff can be trained. Thus, this study suggests integrating this device into community and primary health centers to expand UNHS coverage.

Plasma 21-deoxycortisone: a sensitive additive tool in 21-hydroxylase deficiency in newborns.

OBJECTIVE, DESIGN, AND METHODS: Although 17-hydroxyprogesterone (17OHP) has historically been the steroid assayed in the diagnosis of congenital adrenal 21-hydroxylase deficiency (CAH-21D), its C11-hydroxylated metabolite, 21-deoxycortisol (21DF), which is strictly of adrenal origin, is assayed in parallel in this pathology. This steroid (21DF) is oxidized by 11beta-hydroxysteroid dehydrogenase type 2 into 21-deoxycortisone (21DE). In the context of CAH-21D confirmation testing, confounding factors (such as intensive care unit admission, stress, prematurity, early sampling, and variations of sex development) can interfere with the interpretation of the gold-standard biomarkers (17OHP and 21DF). Since its tissue concentrations are especially high in the placenta, we hypothesized that 21DE quantification in the neonatal periods could be an interesting biomarker in addition to 17OHP and 21DF. To verify this hypothesis, we developed a new mass spectrometry-based assay for 21DE in serum and applied it to newborns screened for CAH-21D. RESULTS: In newborns with CAH-21D, the mean serum levels of 21DE reached 17.56 ng/mL (ranging from 8.58 ng/mL to 23.20 ng/mL), and the mean 21DE:21DF ratio was 4.99. In contrast, in newborns without CAH-21D, the 21DE serum levels were low and not statistically different from the analytical 21DE limit of quantification (0.01 ng/mL). CONCLUSION: Basal serum 21DE appears to be a novel sensitive and specific biomarker of CAH-21D in newborns.

Perspectives of parents with lived experience of cytomegalovirus infection, on universal newborn screening for congenital cytomegalovirus (cCMV) in Canada: a patient-led qualitative study.

OBJECTIVE: To understand parental perspectives regarding universal newborn screening (UNS) for congenital cytomegalovirus (cCMV) in Canada. DESIGN: A qualitative, patient-led study using the Patient and Community Engagement Research approach consisting of online focus groups and in-depth individual interviews to understand parental preferences regarding UNS for cCMV. Data were analysed iteratively using inductive thematic analysis and narrative story analysis. SETTING: Canada-wide study conducted via video conference from October to December 2023. PATIENTS: 12 participants from five Canadian provinces who self-identified as 18 years of age or older and as having parental lived experience with cytomegalovirus (CMV) or cCMV participated in the study. RESULTS: We identified three themes: (1) attitudes about UNS for cCMV, including participants' unanimous support for UNS and confirmation that parental anxiety is not a deterrent for screening, (2) cCMV diagnosis, including the importance of coupling cCMV diagnosis with access to treatment and medical support and (3) awareness of cCMV, where participants shared their frustration about the lack of public and pregnant people's awareness of cCMV. CONCLUSIONS: Parental anxiety is not a deterrent for UNS for cCMV. Children with cCMV and their families deserve every opportunity to attain their best possible outcomes. UNS offers children with cCMV access to early intervention if they need it, and also helps to raise awareness and education to prevent future CMV infections.

A rapid and easy-to-use spinal muscular atrophy screening tool based on primers with high specificity and amplification efficiency for SMN1 combined with single-stranded tag hybridization assay.

Spinal muscular atrophy (SMA) is an intractable neuromuscular disorder primarily caused by homozygous deletions in exon 7 of the SMN1 gene. Early diagnosis and prompt treatment of patients with SMA have a significant impact on prognosis, and several therapies have recently been developed. Current SMA screening tests require a significant turnaround time to identify patients with suspected SMA, due both to the interval between the birth of a newborn and the collection of blood for newborn mass screening and the difficulty in distinguishing between SMN1 and SMN2, a paralog gene that requires testing in specialized laboratories. The aim of this study was therefore to develop a novel SMA screening assay that can be rapidly performed in ordinary hospitals and clinics to overcome these issues. We designed over 100 combinations of forward and reverse primers with 3' ends targeting SMN1-specific sites around exon 7, and evaluated their specificity and amplification efficiency by quantitative PCR to identify the best primer pair. Furthermore, we performed a single-stranded tag hybridization assay after PCR. To evaluate the accuracy and practicality of the newly developed assay, we analyzed saliva specimens from five patients with SMA and two SMA carriers collected in an outpatient clinic and DNA specimens from three patients with SMA and four SMA carriers from a biobank, together with those from healthy individuals. DNA and raw saliva specimens from all patients with SMA demonstrated a biallelic loss of SMN1, whereas those from carriers and healthy individuals did not. The results of 50 independent experiments were consistent for all samples. The assay could be completed within one hour. This simple and convenient new screening tool has the potential to allow patients with SMA to receive disease-modifying therapies within a shorter timeframe.

Breastfeeding in PKU and Other Amino Acid Metabolism Disorders-A Single Centre Experience.

In addition to the numerous immunological and nutritional benefits that breast milk offers to infants, its proportion in the diet must be limited or even excluded in the case of inborn errors of amino acid metabolism (IEM). The objective of the study was to expand knowledge about breastfeeding and the degree of contribution of breast milk to the feeding of infants with IEM before and after the introduction of expanded newborn screening. A retrospective single-centre study was conducted on 127 infants born between 1997 and 2020: 66 with phenylketonuria (PKU), 45 with other IEM (non-PKU), all diagnosed through newborn screening (NBS), and 16 non-PKU diagnosed through selective screening (SS). The time of initiation of dietary treatment and the proportion of breast milk in the diet, both expressed and breastfed, with or without intake control, were analysed at 1, 3, and 6 months after birth. For 47% of the newborns in Groups 1 and 2, the dietary treatment was started before the 10th day of life; in Group 3, the dietary treatment was started after the 10th day of life for all children. During the first month of life, the proportion of infants receiving breast milk was higher in the NBS-PKU (74%) and the NBS non-PKU (80%) groups, compared with 38% in the SS non-PKU infants. In the subsequent months of life, the proportion of infants receiving human milk (either from the breast or a bottle) declined in all groups. This decline occurred more in bottle-fed rather than directly breast-fed infants. Our observations indicate that the model of feeding from a bottle with expressed milk may have had an adverse effect on maintaining lactation and may have contributed to a faster transition to formula milk. Maintaining lactation and extending the period of feeding the infant with human milk in the first 6 months of life is possible by breastfeeding on demand, under regular biochemical monitoring: preferably weekly in PKU infants, and at least every 2-4 weeks in infants with other IEM.

Clues for Early Diagnosis of MEN2B Syndrome Before Medullary Thyroid Carcinoma.

Early onset medullary thyroid carcinoma, later pheochromocytomas, and nonspecific extra-endocrine features (hypermobility and persistent constipation) are part of the clinical phenotype of Multiple Endocrine Neoplasia type 2B (MEN2B). A de novo pathogenic M918T variant in the rearranged during transfection proto-oncogene is usually identified. Affected children are often seen by multiple clinicians over a long period before consideration of a diagnosis of MEN2B, with metastatic medullary thyroid carcinoma often the precipitator. We describe the clinical presentation and course of 5 children ultimately diagnosed with MEN2B in New South Wales and the Australian Capital Territory, Australia between 1989 and 2021. All cases had intestinal ganglioneuromatosis that could have prompted an earlier diagnosis. Population wide newborn genomic screening for rare diseases is on the horizon. We propose that MEN2B genomic screening should be included in newborn screening programs and that careful exclusion of intestinal ganglioneuromatosis would allow earlier identification leading to improved clinical outcomes.

Genetic screening of newborns for deafness over 11 years in Beijing, China: More infants could benefit from an expanded program.

Genetic screening of newborns for deafness plays an important role in elucidating the etiology of deafness, diagnosing it early, and intervening in it. Genetic screening of newborns has been conducted for 11 years in Beijing. It started with a chip to screen for 9 variants of 4 genes in 2012; the chip screened for 15 variants of those genes in 2018, and it now screens for 23 variants of those genes. In the current study, a comparative analysis of three screening protocols and follow-up for infants with pathogenic variants was performed. The rates of detection and hearing test results of infants with pathogenic variants were analyzed. Subjects were 493,821 infants born at 122 maternal and child care centers in Beijing from April 2012 to August 2023. Positivity increased from 4.599% for the chip to screen for 9 variants to 4.971% for the chip to screen for 15 variants, and further to 11.489% for the chip to screen for 23 variants. The carrier frequency of the GJB2 gene increased from 2.489% for the chip to screen for 9 variants and 2.422% for the chip to screen for 15 variants to 9.055% for the chip to screen for 23 variants. The carrier frequency of the SLC26A4 gene increased from 1.621% for the chip to screen for 9 variants to 2.015% for the chip to screen for 15 variants and then to 2.151% for the chip to screen for 23 variants. According to the chip to screen for 9 variants and the chip to screen for 15 variants, the most frequent mutant allele was c.235delC. According to the chip to screen for 23 variants, the most frequent mutant allele was c.109G>A. The chip to screen for 15 variants was used to screen 66.67% (14/21) of newborns with biallelic variants in the SLC26A4 gene for newly added mutations. The chip to screen for 23 variants was used to screen 92.98% (53/57) of newborns with biallelic variants in the GJB2 gene (52 cases were biallelic c.109G>A) and 25% (1/4) of newborns with biallelic variants in the SLC26A4 gene for newly added mutations. Among the infants with pathogenic variants (biallelic variants in GJB2 or SLC26A4), 20.66% (25/121) currently have normal hearing. In addition, 34.62% (9/26) of newborns who passed the hearing screening were diagnosed with hearing loss. Findings indicate that a growing number of newborns have benefited, and especially in the early identification of potential late-onset hearing loss, as the number of screening sites has increased. Conducting long-term audiological monitoring for biallelic variants in individuals with normal hearing is of paramount significance.

Patients with Thyroid Dyshormonogenesis and DUOX2 Variants: Molecular and Clinical Description and Genotype-Phenotype Correlation.

Thyroid dyshormonogenesis (THD) is a heterogeneous group of genetic diseases caused by the total or partial defect in the synthesis or secretion of thyroid hormones. Genetic variants in DUOX2 can cause partial to total iodination organification defects and clinical heterogeneity, from transient to permanent congenital hypothyroidism. The aim of this study was to undertake a molecular characterization and genotype-phenotype correlation in patients with THD and candidate variants in DUOX2. A total of 31 (19.38%) patients from the Catalan Neonatal Screening Program presented with variants in DUOX2 that could explain their phenotype. Fifteen (48.39%) patients were compound heterozygous, 10 (32.26%) heterozygous, and 4 (12.90%) homozygous. In addition, 8 (26.67%) of these patients presented variants in other genes. A total of 35 variants were described, 10 (28.57%) of these variants have not been previously reported in literature. The most frequent variant in our cohort was c.2895_2898del/p.(Phe966SerfsTer29), classified as pathogenic according to reported functional studies. The final diagnosis of this cohort was permanent THD in 21 patients and transient THD in 10, according to reevaluation and/or need for treatment with levothyroxine. A clear genotype-phenotype correlation could not be identified; therefore, functional studies are necessary to confirm the pathogenicity of the variants.