Neurosonography: Shaping the future of neuroprotection strategies in extremely preterm infants.

This review aims to explore the current application of Cranial Ultrasound Screening (CUS) in the diagnosis and treatment of brain diseases in extremely preterm infants. It also discusses the potential role of emerging ultrasound-derived technologies such as Super Microvascular Structure Imaging (SMI), Shear Wave Elastography (SWE), Ultrafast Doppler Ultrasound (UfD), and 3D ventricular volume assessment and automated segmentation techniques in clinical practice. A systematic search of medical databases was conducted using the keywords "(preterm OR extremely preterm OR extremely low birth weight) AND (ultrasound OR ultrasound imaging) AND (neurodevelopment OR brain development OR brain diseases OR brain injury OR neuro*)" to identify relevant literature. The titles, abstracts, and full texts of the identified articles were carefully reviewed to determine their relevance to the research topic. CUS offers unique advantages in early screening and monitoring of brain diseases in extremely preterm infants, as it can be performed at the bedside without the need for anesthesia or special monitoring. This technique facilitates early detection and intervention of conditions such as intraventricular hemorrhage, white matter injury, hydrocephalus, and hypoxic-ischemic injury in critically ill preterm infants. Continuous refinement of the screening and follow-up processes provides reliable clinical decision-making support for healthcare professionals and parents. Emerging ultrasound technologies, such as SWE, SMI, and UfD, are being explored to provide more accurate and in-depth understanding of brain diseases in extremely preterm infants. SWE has demonstrated its effectiveness in assessing the elasticity of neonatal brain tissue, aiding in the localization and quantification of potential brain injuries. SMI can successfully identify microvascular structures in the brain, offering a new perspective on neurologic diseases. UfD provides a high-sensitivity and quantitative imaging method for the prevention and treatment of neonatal brain diseases by detecting subtle changes in red blood cell movement and accurately assessing the status and progression of brain diseases. CUS and its emerging technologies have significant applications in the diagnosis and treatment of brain diseases in extremely preterm infants. Future research aims to address current technical challenges, optimize and enhance the clinical decision-making capabilities related to brain development, and improve the prevention and treatment outcomes of brain diseases in extremely preterm infants.

Genotype and phenotype features and prognostic factors of neonatal-onset pyridoxine-dependent epilepsy: A systematic review.

Pyridoxine-dependent epilepsy (PDE-ALDH7A1) is a rare autosomal recessive disorder due to a deficiency of α-aminoadipic semialdehyde dehydrogenase. This study aimed to systematically explore genotypic and phenotypic features and prognostic factors of neonatal-onset PDE. A literature search covering PubMed, Elsevier, and Web of Science was conducted from January 2006 to August 2023. We identified 56 eligible studies involving 169 patients and 334 alleles. The c.1279 G>C variant was the most common variant of neonatal-onset PDE (25.7 %). All patients were treated with pyridoxine; forty patients received dietary intervention therapy. 63.9 % of the patients were completely seizure-free; however, 68.6 % of the patients had neurodevelopmental delays. Additionally, homozygous c.1279 G>C variants were significantly associated with ventriculomegaly, abnormal white matter signal, and cysts (P<0.05). In contrast, homozygous c.1364 T>C was associated with clonic seizure (P=0.031). Pyridoxine used immediately at seizure onset was an independent protective factor for developmental delay (P=0.035; odds ratio [OR]: 3.14). Besides, pyridoxine used early in the neonatal period was a protective factor for language delay (P=0.044; OR: 4.59). In contrast, neonatal respiratory distress (P=0.001; OR: 127.44) and abnormal brain magnetic resonance imaging (P=0.049; OR: 3.64) were risk factors. Prenatal movement abnormality (P=0.041; OR: 20.56) and abnormal white matter signal (P=0.012; OR: 24.30) were risk factors for motor delay. Myoclonic seizure (P=0.023; OR: 7.13) and status epilepticus (P=0.000; OR: 9.93) were risk factors for breakthrough seizures. In conclusion, our study indicated that pyridoxine should be started immediately when unexplained neonatal seizures occur and not later than the neonatal period to prevent poor neurodevelopmental outcomes.

Brain development in newborns and infants after ECMO.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) not only significantly improves survival rates in severely ill neonates but also is associated with long-term neurodevelopmental issues. To systematically review the available literature on the neurodevelopmental outcomes of neonates and infants who have undergone ECMO treatment, with a focus on motor deficits, cognitive impairments, sensory impairments, and developmental delays. This review aims to understand the incidence, prevalence, and risk factors for these problems and to explore current nursing care and management strategies. DATA SOURCES: A comprehensive literature search was performed across PubMed, EMBASE, and Web of Science using a wide array of keywords and phrases pertaining to ECMO, neonates, infants, and various facets of neurodevelopment. The initial screening involved reviewing titles and abstracts to exclude irrelevant articles, followed by a full-text assessment of potentially relevant literature. The quality of each study was evaluated based on its research methodology and statistical analysis. Moreover, citation searches were conducted to identify potentially overlooked studies. Although the focus was primarily on neonatal ECMO, studies involving children and adults were also included due to the limited availability of neonate-specific literature. RESULTS: About 50% of neonates post-ECMO treatment exhibit varying degrees of brain injury, particularly in the frontal and temporoparietal white matter regions, often accompanied by neurological complications. Seizures occur in 18%-23% of neonates within the first 24 hours, and bleeding events occur in 27%-60% of ECMO procedures, with up to 33% potentially experiencing ischemic strokes. Although some studies suggest that ECMO may negatively impact hearing and visual development, other studies have found no significant differences; hence, the influence of ECMO remains unclear. In terms of cognitive, language, and intellectual development, ECMO treatment may be associated with potential developmental delays, including lower composite scores in cognitive and motor functions, as well as potential language and learning difficulties. These studies emphasize the importance of early detection and intervention of potential developmental issues in ECMO survivors, possibly necessitating the implementation of a multidisciplinary follow-up plan that includes regular neuromotor and psychological evaluations. Overall, further multicenter, large-sample, long-term follow-up studies are needed to determine the impact of ECMO on these developmental aspects. CONCLUSIONS: The impact of ECMO on an infant's nervous system still requires further investigation with larger sample sizes for validation. Fine-tuned management, comprehensive nursing care, appropriate patient selection, proactive monitoring, nutritional support, and early rehabilitation may potentially contribute to improving the long-term outcomes for these infants.

Genetic spectrums and clinical profiles of critically ill neonates with congenital auricular deformity in the China Neonatal Genomes Project.

Congenital auricular deformity (CAD) is a complex phenotype that may occur as a single malformation or part of a congenital syndrome. The genetic architecture and utility of next-generation sequencing (NGS) in a sizable cross-sectional study of critically ill neonates with CAD have not yet been systematically investigated. This cross-sectional study investigated the genetic spectrum in critically ill neonates with CADs. Critically ill neonates with CADs (n = 251) were enrolled between August 8, 2016 and October 1, 2022. All neonates underwent NGS. The outcomes were molecular diagnostic yield, spectrum of genetic events, and clinical findings. Genetic findings were obtained in 107 neonates (42.6%), of which 67.3% (72/107) had pathogenic/likely pathogenic/variants of uncertain significance (P/LP/VUS) gene variations and 32.7% (35/107) had P/LP/VUS copy number variations (CNVs). The diagnostic rates of clinical exome sequencing were similar to those of exome sequencing. The logistic regression model revealed that CAD neonates with craniofacial abnormalities (OR = 4.15, 95% CI 2.29-7.53) or cardiovascular malformation (OR = 2.09, 95% CI 1.14-3.84) are more likely to be attributed to genetic causes. Follow-up analysis revealed that, compared to those in the undiagnosed group, the number of neonates whose care was withdrawn or who died was higher in the genetically diagnosed group (P < 0.05). This study identified a high incidence of genetic causes in critically ill neonates with CADs, with a combination of single-nucleotide variations and CNVs among the genetic causes of CAD. These findings highlight potential of NGS in the genetic testing of critically ill neonates with CADs.

Incidence of Neonatal Seizures in China Based on Electroencephalogram Monitoring in Neonatal Neurocritical Care Units.

Importance: Neonatal seizures pose a significant challenge in critical care, and continuous video electroencephalography (cEEG) monitoring holds promise for early detection of seizures. However, large-scale data on the incidence of neonatal seizures and monitoring systems in China are lacking. Objectives: To determine the incidence of neonatal seizures in infants with high risk in China. Design, Setting, and Participants: A large, cross-sectional multicenter study was conducted from January 2017 to December 2018 in the neonatal intensive care units (NICUs) of 7 tertiary medical centers in China. Neonates with high risk were included, and cEEG monitoring was conducted. Data were collected between January 1, 2017, and January 31, 2020. The data were analyzed between January 2021 and January 2022. Main Outcomes and Measures: The incidence of neonatal seizures, categorized by etiology, and seizure burden. Results: A total of 20 310 neonates with high risk were included (10 495 [51.7%] male; mean [SD] postmenstrual age, 37.7 [3.7] weeks), and seizures were observed in 3423 infants (16.9%). The highest proportion of seizures was attributed to acute neonatal encephalopathy (1448 [42.3%]). The incidence of seizures decreased with postmenstrual age and birth weight, with the highest occurrence observed in neonates with postmenstrual age of less than 28 weeks (237 of 879 [27.0%]) or birth weight of less than 1.0 kg (269 of 914 [29.4%]). Preterm infants had a higher proportion of moderate and severe seizure burdens compared with full-term infants (moderate severity: 248 of 1199 [20.7%] vs 454 of 2224 [20.4%]), but no significant differences were observed in etiology. Seizure burden was highest with genetic syndromes (49 of 188 [26.1%]), central nervous system malformations (33 of 127 [26.0%]), and inborn errors of metabolism (27 of 113 [23.9%]). During hospitalization, 7.8% of neonates with seizures died (267 neonates), with 81.3% of these cases having a moderate or severe seizure burden (217 neonates). Mortality was generally higher in preterm vs full-term infants (98 of 1199 [8.2%] vs 169 of 2224 [7.6%]) and increased with the severity of seizure burden (217 of 267 neonates with moderate or severe burden [81.3%]). Conclusions and Relevance: This cross-sectional study of neonatal seizures underscores the substantial burden seizures pose to high-risk infants with brain injury in China, particularly those who are born prematurely or who have congenital conditions.

Fourteen cases of cerebral creatine deficiency syndrome in children: a cohort study in China.

Background: This study sought to analyze the clinical characteristics, biochemical metabolic indications, treatment results, and genetic spectrum of cerebral creatine deficiency syndrome (CCDS), estimate the prevalence of CCDS in Chinese children and provide a reference to guide clinical practice. Methods: We performed a retrospective cohort study of 3,568 children with developmental delay at Children's Hospital of Fudan University over a 6-year period (January 2017-December 2022). Metabolites in the blood/urine were detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and genetic testing was performed by next-generation sequencing (NGS). The patients with suspected CCDS were ultimately diagnosed by magnetic resonance spectroscopy (MRS). The patients were then treated and followed up. All the reported cases of CCDS, their gene mutations, and treatment results in China were summarized. Results: Ultimately, 14 patients were diagnosed with CCDS. The age of onset was between 1-2 years. All the patients had developmental delay, 9 had epilepsy, and 8 had movement or behavioral disorders. A total of 17 genetic variants were identified, including 6 novel variants. c.403G>A, c.491dupG of the guanidinoacetate methyltransferase (GAMT) gene had a relatively high frequency. After treatment, patients with GAMT deficiency showed obvious improvements, and brain creatine (Cr) levels recovered to 50-80% of normal, 1 patient achieved normal neurodevelopment, and 3 patients became epilepsy free; however, 6 male patients with X-linked creatine transporter gene (SLC6A8) variants received Cr for 3-6 months with no effect, and 2 patients received combined therapy with few improvements. Conclusions: The prevalence of CCDS is ~0.39% in Chinese children with developmental delay. A low-protein diet, Cr and, ornithine were useful for patients with GAMT deficiency. Male patients with SLC6A8 deficiency showed only limited improvement on combined therapy.

Risk stratification of hemodynamically significant patent ductus arteriosus by clinical and genetic factors.

BACKGROUND: Hemodynamically significant patent ductus arteriosus (hsPDA) is associated with increased comorbidities in neonates. Early evaluation of hsPDA risk is critical to implement individualized intervention. The aim of the study was to provide a powerful reference for the early identification of high-risk hsPDA population and early treatment decisions. METHODS: We enrolled infants who were diagnosed with PDA and performed exome sequencing. The collapsing analyses were used to find the risk gene set (RGS) of hsPDA for model construction. The credibility of RGS was proven by RNA sequencing. Multivariate logistic regression was performed to establish models combining clinical and genetic features. The models were evaluated by area under the receiver operating curve (AUC) and decision curve analysis (DCA). RESULTS: In this retrospective cohort study of 2199 PDA patients, 549 (25.0%) infants were diagnosed with hsPDA. The model [all clinical characteristics selected by least absolute shrinkage and selection operator regression (all CCs)] based on six clinical variables was acquired within three days of life, including gestational age (GA), respiratory distress syndrome (RDS), the lowest platelet count, invasive mechanical ventilation, and positive inotropic and vasoactive drugs. It has an AUC of 0.790 [95% confidence interval (CI) = 0.749-0.832], while the simplified model (basic clinical characteristic model) including GA and RDS has an AUC of 0.753 (95% CI = 0.706-0.799). There was a certain consistency between RGS and differentially expressed genes of the ductus arteriosus in mice. The AUC of the models was improved by RGS, and the improvement was significant (all CCs vs. all CCs + RGS: 0.790 vs. 0.817, P < 0.001). DCA demonstrated that all models were clinically useful. CONCLUSIONS: Models based on clinical factors were developed to accurately stratify the risk of hsPDA in the first three days of life. Genetic features might further improve the model performance. Video Abstract (MP4 86834 kb).

Comparison of Genetic Profiles of Neonates in Intensive Care Units Conceived With or Without Assisted Reproductive Technology.

Importance: A growing number of children are conceived with assisted reproductive technology (ART). However, there is a lack of studies systematically analyzing the genetic landscape of live-born children conceived through ART who need intensive care in the neonatal period. Objective: To investigate the incidence and type of molecular defects among neonates conceived through ART who are in intensive care units (NICUs) with suspected genetic conditions. Design, Setting, and Participants: This was a cross-sectional study using data from the China Neonatal Genomes Project, a multicenter national neonatal genome data set managed by the Children's Hospital of Fudan University. All participants were from level III and IV NICUs and included 535 neonates conceived through ART with suspected genetic conditions, with data collected between August 1, 2016, and December 31, 2021, and 1316 naturally conceived neonates with suspected genetic conditions in the same clinical settings, with data collected between August 1, 2016, and December 31, 2018. The data were analyzed between September 2021 and January 2023. Exposures: Whole-exome sequencing or target clinical exome sequencing with pathogenic or likely pathogenic single-nucleotide variant (SNV) and copy number variation (CNV) detection was performed for each individual. Main Outcomes and Measures: The primary outcome was the molecular diagnostic yield, mode of inheritance, spectrum of genetic events, and incidence of de novo variants. Results: A total of 535 neonates conceived through ART (319 boys [59.6%]) and 1316 naturally conceived neonates (772 boys [58.7%]) were included. A genetic diagnosis was established for 54 patients conceived through ART (10.1%), including 34 patients with SNVs (63.0%) and 20 with CNVs (37.0%). In the non-ART group, 174 patients (13.2%) received a genetic diagnosis, including 120 patients with SNVs (69.0%) and 54 with CNVs (31.0%). The overall diagnostic yield was comparable between the ART group and the naturally conceived neonates (10.1% vs 13.2%; odds ratio [OR], 0.74; 95% CI, 0.53-1.02), as was the proportion of SNVs (63.0% vs 69.0%; OR, 0.68; 95% CI, 0.46-1.00) and CNVs (37.0% vs 31.0%; OR, 0.91; 95% CI, 0.54-1.53) detected by sequencing. Furthermore, the proportions of de novo variants in the ART group and the non-ART group were similar (75.9% [41 of 54] vs 64.4% [112 of 174]; OR, 0.89; 95% CI, 0.62-1.30). Conclusions and Relevance: This cross-sectional study of neonates in NICUs suggests that the overall genetic diagnostic yield and the incidence of de novo variants were similar between live-born neonates conceived through ART and naturally conceived neonates in the same settings.

[Clinical practice of whole-genome sequencing in the rapid diagnosis of critically ill neonates]. / é‡‡ç”¨å ¨åŸºå› ç»„æµ‹åºæŠ€æœ¯å¿«é€Ÿè¯Šæ–­å±é‡ç—‡æ–°ç”Ÿå„¿çš„ä¸´åºŠå®žè·µ.

OBJECTIVES: To explore the application of whole-genome sequencing (WGS) in the rapid clinical diagnosis of critically ill neonates. METHODS: The critically ill neonates who admitted to the neonatal intensive care unit of Children's Hospital of Fudan University and underwent WGS from August to September, 2019 were enrolled in this prospective study. The genetic testing results and clinical outcome were analyzed with reference to the sequencing data and clinical features of the neonates. RESULTS: A total of 15 neonates were tested, among whom there were 9 boys and 6 girls. The main reason for hospitalization included abnormal breathing in 7 neonates, poor response in 2 neonates, feeding difficulty in 2 neonates, fever in 1 neonate, hypothermia in 1 neonate, preterm birth in 1 neonate, and convulsion in 1 neonate. The mean turn-around time was 4.5 days for WGS. Finally a genetic diagnosis was obtained for 3 neonates, with a positive diagnostic rate of 20% (3/15). Among the 3 neonates, 2 neonates were withdrawn from the treatment due to severe conditions and 1 neonate died on the day when the sample was sent for genetic testing, whose etiology could be explained by the results of genetic testing. CONCLUSIONS: WGS technique can provide a timely and effective diagnosis for critically ill neonates suspected of genetic diseases and provide genetic evidence for clinical treatment of critically ill cases.

Genetic architecture in neonatal intensive care unit patients with congenital heart defects: a retrospective study from the China Neonatal Genomes Project.

BACKGROUND: Congenital heart defects (CHDs) are the most common type of birth defects. The genetic aetiology of CHD is complex and incompletely understood. The overall distribution of genetic causes in patients with CHD from neonatal intensive care units (NICUs) needs to be studied. METHODS: CHD cases were extracted from the China Neonatal Genomes Project (2016-2021). Next-generation sequencing results and medical records were retrospectively evaluated to note the frequency of genetic diagnosis and the respective patient outcomes. RESULTS: In total, 1795 patients were included. The human phenotype ontology term of atrial septal defect, patent ductus arteriosus and ventricular septal defect account for a large portion of the CHD subtype. Co-occurring extracardiac anomalies were observed in 35.1% of patients. 269 of the cases received genetic diagnoses that could explain the phenotype of CHDs, including 172 copy number variations and 97 pathogenic variants. The detection rate of trio-whole-exome sequencing was higher than clinical exome sequencing (21.8% vs 14.5%, p<0.05). Further follow-up analysis showed the genetic diagnostic rate was higher in the deceased group than in the surviving group (29.0% vs 11.9%, p<0.05). CONCLUSION: This is the largest cohort study to explore the genetic spectrum of patients with CHD in the NICU in China. Our findings may benefit future work on improving genetic screening and counselling for NICU patients with CHD.

Monkeypox and the perinatal period: what does maternal-fetal medicine need to know?

BACKGROUND: After the global elimination of smallpox, monkeypox has become the most threatening orthopoxvirus to human health. Very few studies have been reported on pregnant women and newborns. In the case of monkeypox infection, the virus can cause serious adverse pregnancy events in women, which can lead to fetal or neonatal death. DATA SOURCES: We made a comprehensive review after an extensive literature search in the PubMed/Medline database and websites concerning smallpox and monkeypox. RESULTS: Two case reports reported a total of nine pregnant women, six of whom had fetal deaths. In the autopsy of a stillbirth, researchers found that the placenta was infected with monkeypox virus, but the mechanism of infection remains unclear. Smallpox vaccine should be administered to acutely exposed pregnant women and newborns. Several novel recombinant vaccinia immunogloblin (rVIG) and human-specific monoclonal antibodies are being developed for the prevention and treatment of monkeypox virus infection. After the fetus was delivered, the newborn should take a bath as soon as possible to remove the amniotic fluid and dirt from the body. The appropriate isolation protocol for the newborn should be selected according to the infection status of the mother. It is not known whether monkeypox virus is present in breast milk, and pasteurized breast milk can be given to newborns when breastfeeding is considered. CONCLUSION: This review presents an overview of monkeypox in the perinatal period and guides the future research direction.

Clinical features of infants with SARS-CoV-2 infection: a systematic review and meta-analysis.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) leads to coronavirus disease 2019 (COVID-19) and is a public health problem. This meta-analysis reviewed the clinical features of SARS-CoV-2 infection among infants. METHODS: PubMed, Scopus, Web of Science, and the Cochrane Library were searched for studies on clinical features of infants with SARS-CoV-2 published before May 1, 2022. Two authors screened and extracted data on the number of infants with SARS-CoV-2 infection, clinical features, and number of clinical features. The proportion of asymptomatic infection, mild symptoms, moderate symptoms, severe symptoms, and the clinical features were analyzed. RESULTS: Forty-four studies with 6,304 infants with SARS-CoV-2 infections were included in this study. The proportion of asymptomatic infection was 20% (95% CI: 11-28%, I2=97%, P<0.01) in infants with SARS-CoV-2 infections. The proportion of infants with mild, moderate, and severe symptoms was 48% (95% CI: 30-65%, I2=96%, P<0.01), 27% (95% CI: 10-44%, I2=93%, P<0.01), and 8% (95% CI: 0-16%, I2=90%, P<0.01), respectively. Notably, the most common clinical features of infants with SARS-CoV-2 infection were fever (64%), cough (34%), and nasal symptoms (31%). CONCLUSIONS: This meta-analysis found that 20% of infants with SARS-CoV-2 infections were asymptomatic, while most infants with COVID-19 presented with mild symptoms.

Overcoming the Pitfalls of Next-Generation Sequencing-Based Molecular Diagnosis of Shwachman-Diamond Syndrome.

Shwachman-Diamond syndrome (SDS) is the second most common cause of exocrine pancreatic insufficiency, and 90% of patients carry mutations in the SBDS gene, the most common being the c.183_184delinsCT and c.258+2T>C variants. However, precise detection of these most contributory variants by conventional short-read next-generation sequencing data analysis is limited because of the SBDS/SBDSP1 highly homologous sequences. In this study, an efficient approach was established to infer the haplotype of SBDS based on the expectation-maximization algorithm. The workflow was retrospectively applied to detect the two most common SBDS variants in a Chinese SDS high-risk cohort, and a systematic comparison of variant detection results was performed between the workflow and conventional next-generation sequencing analysis based on Sanger sequencing validation. Among the Chinese SDS high-risk cohort (n = 47) and their available parents (n = 64), the established workflow improved the diagnostic rate for these two variants by 27.7% (95% CI, 15.6%-42.6%) compared with conventional analysis. For overall variant detection, the established workflow achieved 100% (95% CI, 92.5%-100%) concordance with Sanger sequencing, whereas conventional analysis showed only 65.8% accuracy; these results included 25.2% with missed variant calls, 7.2% with diagnosed but inaccurate variant calls, and 1.8% with false-positive calls. With its favorable result in both SDS patient diagnosis and carrier detection performance, the provided workflow showed its potential in clinical application for SDS molecular diagnosis.

Diagnostic utility of rapid sequencing in critically ill infants: a systematic review and meta-analysis.

BACKGROUND: Genetic disorders are a major cause of death in critically ill infants. Several studies have assessed the diagnostic yield of rapid genomic sequencing in critically ill infants. This meta-analysis aimed to summarize the diagnostic utility of rapid genomic sequencing in critically ill infants. METHODS: PubMed, Scopus, Web of Science, and Cochrane Library, were searched before 1 July 2022. Studies reported diagnostic rate of rapid genomic sequencing in critically ill infants were selected. Two authors screened and extracted data regarding the method of genetic test, total number of patients, and number of diagnosed patients. RESULTS: Twenty-three studies, comprising 1567 critically ill infants were included in the meta-analysis. In the overall analysis, the pooled diagnostic utility of rapid genomic sequencing was 0.42 (95% CI: 0.37-0.49, I2 = 79%, P < 0.1). Moreover, the pooled diagnostic rates of rapid whole-exome and rapid whole-genome sequencing were 0.50 (95% CI: 0.41-0.61; I2 = 74%; P < 0.01) and 0.37 (95% CI: 0.30-0.46; I2 = 77%; P < 0.01), respectively. Sensitive analysis showed that the results were stable in the overall analysis. Additionally, publication bias was not observed in the overall analysis. CONCLUSIONS: This meta-analysis proved that rapid genomic sequencing has a good diagnostic utility for critically ill infants.

Systematic estimation of cystic fibrosis prevalence in Chinese and genetic spectrum comparison to Caucasians.

BACKGROUND: Cystic fibrosis (CF) is a common, life-threatening genetic disease in Caucasians but rarely reported in Chinese population. The prevalence and population-specific genetic spectrum of CF in China needs to be systematically estimated and compared with Caucasians. MATERIALS AND METHODS: We reviewed 30,951 exome-sequencing samples, including 20,909 pediatric patient samples and 10,042 parent samples, from Chinese Children's Rare Disease Genetic Testing Clinical Collaboration System (CCGT). After the in-lab filtration process, 477 candidate variants of CFTR gene were left and 53 variants were manually curated as pathogenic/likely-pathogenic (P/LP). These P/LP variants were adopted to estimate CF prevalence in three methods: the carrier frequency method, the permutation-combinations method and the Bayesian framework method. Allele frequencies of the 477 CFTR variants were compared with non-Finland European (NFE) and East Asian (EAS) from gnomAD database. To investigate the haplotype structure difference of CFTR, another 2067 whole-genome-sequencing samples from CCGT and 195 NFE from 1000 genome project were analyzed by Shapeit4 software. RESULT: With the 53 manually curated P/LP variants in CFTR gene, we excluded individuals identified or suspected with CF and their parents in our cohorts and estimated the Chinese CF prevalence is approximately 1/128,434. Only 21 (39.6%) of the 53 variants were included in Caucasian specific CF screening panels, resulting in significantly under-estimation of CF prevalence in our children cohort (1/143,171 vs. 1/1,387,395, P = 5e-24) and parent's cohort (1/110,127 vs. 1/872,437, P = 7e-10). The allele frequencies of six pathogenic variants (G970D, D979A, M469V, G622D, L88X, 1898+5G->T) were significantly higher in our cohorts compared with gnomAD-NFE population (all P-value < 0.1). Haplotype analysis showed more haplotype diversity in Chinese compared to Caucasians. In addition, G970D and F508del were founder mutation of Chinese and Caucasians with two SNPs (rs213950-rs1042077) identified as related genotype in exon region. CONCLUSIONS: Chinese population showed significantly different genetic spectrum pattern in CFTR gene compared with Caucasian population, and thus a Chinese-specific CF screening panel is needed.

Neonatal Metabolic Acidosis in the Neonatal Intensive Care Unit: What Are the Genetic Causes?

Neonatal metabolic acidosis (NMA) is a common problem, particularly in critically ill patients in neonatal intensive care units (NICUs). Complex etiologies and atypical clinical signs make diagnosis difficult; thus, it is crucial to investigate the underlying causes of NMA rapidly and provide disorder-specific therapies. Our study aims to provide an overview of the genetic causes of NMA in patients from NICUs. We performed next-generation sequencing (NGS) on neonates with NMA from January 2016 to December 2019. Clinical features, genetic diagnoses, and their effects on clinical interventions were collected for analysis. In the 354 enrolled patients, 131 (37%) received genetic diagnoses; 95 (72.5%) of them were autosomal recessively inherited diseases. Two hundred and fifteen variants spanning 57 genes were classified as pathogenic (P) or likely pathogenic (LP) in 131 patients. The leading cause was metabolic disorders due to 35 genes found in 89 patients (68%). The other 42 NMA patients (32%) with 22 genes had malformations and renal, neuromuscular, and immune-hematological disorders. Seven genes (MMUT, MMACHC, CHD7, NPHS1, OTC, IVD, and PHOX2B) were noted in more than four patients, accounting for 48.9% (64/131) of the identified P/LP variants. Forty-six diagnosed patients with uncorrected NMA died or gave up. In conclusion, 37% of neonates with metabolic acidosis had genetic disorders. Next-generation sequencing should be considered when investigating the etiology of NMA in NICUs. Based on early molecular diagnoses, valuable treatment options can be provided for some genetic diseases to achieve better outcomes.

High-Frequency Exon Deletion of DNA Cross-Link Repair 1C Accounting for Severe Combined Immunodeficiency May Be Missed by Whole-Exome Sequencing.

Next-generation sequencing (NGS) has been used to detect severe combined immunodeficiency (SCID) in patients, and some patients with DNA cross-link repair 1C (DCLRE1C) variants have been identified. Moreover, some compound variants, such as copy number variants (CNV) and single nucleotide variants (SNV), have been reported. The purpose of this study was to expand the genetic data related to patients with SCID carrying the compound DCLRE1C variant. Whole-exome sequencing (WES) was performed for genetic analysis, and variants were verified by performing Sanger sequencing or quantitative PCR. Moreover, we searched PubMed and summarized the data of the reported variants. Four SCID patients with DCLRE1C variants were identified in this study. WES revealed a homozygous deletion in the DCLRE1C gene from exons 1-5 in patient 1, exons 1-3 deletion and a novel rare variant (c.92T>C, p.L31P) in patient 2, exons 1-3 deletion and a novel rare variant (c.328C>G, p.L110V) in patient 3, and exons 1-4 deletion and a novel frameshift variant (c.449dup, p.His151Alafs*20) in patient 4. Based on literature review, exons 1-3 was recognized as a hotspot region for deletion variation. Moreover, we found that compound variations (CNV + SNV) accounted for approximately 7% variations in all variants. When patients are screened for T-cell receptor excision circles (TRECs), NGS can be used to expand genetic testing. Deletion of the DCLRE1C gene should not be ignored when a variant has been found in patients with SCID.

Combining Metagenomic Sequencing With Whole Exome Sequencing to Optimize Clinical Strategies in Neonates With a Suspected Central Nervous System Infection.

Objectives: Central nervous system (CNS) infection has a high incidence and mortality in neonates, but conventional tests are time-consuming and have a low sensitivity. Some rare genetic diseases may have some similar clinical manifestations as CNS infection. Therefore, we aimed to evaluate the performance of metagenomic next-generation sequencing (mNGS) in diagnosing neonatal CNS infection and to explore the etiology of neonatal suspected CNS infection by combining mNGS with whole exome sequencing (WES). Methods: We prospectively enrolled neonates with a suspected CNS infection who were admitted to the neonatal intensive care unit(NICU) from September 1, 2019, to May 31, 2020. Cerebrospinal fluid (CSF) samples collected from all patients were tested by using conventional methods and mNGS. For patients with a confirmed CNS infection and patients with an unclear clinical diagnosis, WES was performed on blood samples. Results: Eighty-eight neonatal patients were enrolled, and 101 CSF samples were collected. Fourty-three blood samples were collected for WES. mNGS showed a sample diagnostic yield of 19.8% (20/101) compared to 4.95% (5/101) for the conventional methods. In the empirical treatment group, the detection rate of mNGS was significantly higher than that of conventional methods [27% vs. 6.3%, p=0.002]. Among the 88 patients, 15 patients were etiologically diagnosed by mNGS alone, five patients were etiologically identified by WES alone, and one patient was diagnosed by both mNGS and WES. Twelve of 13 diagnoses based solely on mNGS had a likely clinical effect. Six patients diagnosed by WES also experienced clinical effect. Conclusions: For patients with a suspected CNS infections, mNGS combined with WES might significantly improve the diagnostic rate of the etiology and effectively guide clinical strategies.

Amplitude of low-frequency fluctuation may be an early predictor of delayed motor development due to neonatal hyperbilirubinemia: a fMRI study.

BACKGROUND: Acute bilirubin encephalopathy or kernicterus is the worst consequence of brain damage caused by the elevation of total unbound serum bilirubin (TSB) in neonates. The present study aimed to visualize the characteristic brain regions of neonates with hyperbilirubinemia (HB) using functional magnetic resonance imaging (fMRI) and to measure the amplitude of low-frequency fluctuation (ALFF) values. METHODS: This was a prospective cohort study, which included newborns with HB who were hospitalized at the Children's Hospital of Fudan University. The control group included neonates admitted with neonatal simple wet lung or pneumonia without neurological disease or brain injury. Newborns were divided into a severe hyperbilirubinemia group (SHB), moderate HB group, and control group based on TSB levels. The newborns completed routine MRI combined with fMRI scans and brainstem auditory evoked potentials (BAEPs) during their hospitalization. RESULTS: A total of 251 newborns were included in this study. There were 45 patients in the SHB group, 65 in the HB group, and 141 in the control group. The average ALFF value in the basal ganglia region in the SHB group was the highest, which was greater than that in the HB and control groups (P<0.001). The ALFF increased with an increase in TSB concentration. Based on the results of the Bayley Scales of infant development assessment, we further found that the most significant difference in ALFF remained in the basal ganglia region between newborns with motor development scores above 70 (including 70) and below 70. Correlation analysis revealed a strong negative correlation between motor development scores and ALFF (r=-0.691, P<0.001). When ALFF alone was used to predict motor development, the sensitivity was 89%. When ALFF was combined with TSB and BEAP results, the area under the ROC curve was the largest (AUC =0.85). The sensitivity and specificity of the model were 67.86% and 90.77%, respectively. CONCLUSIONS: The ALFF value may be able to serve as an early imaging biomarker and has a greater sensitivity than TSB or BAEP results in predicting long-term motor development (18 m) in HB.

Application of Full-Spectrum Rapid Clinical Genome Sequencing Improves Diagnostic Rate and Clinical Outcomes in Critically Ill Infants in the China Neonatal Genomes Project.

OBJECTIVES: To determine the diagnostic and clinical utility of trio-rapid genome sequencing in critically ill infants. DESIGN: In this prospective study, samples from critically ill infants were analyzed using both proband-only clinical exome sequencing and trio-rapid genome sequencing (proband and biological parents). The study occurred between April 2019 and December 2019. SETTING: Thirteen member hospitals of the China Neonatal Genomes Project spanning 10 provinces were involved. PARTICIPANTS: Critically ill infants (n = 202), from birth up until 13 months of life were enrolled based on eligibility criteria (e.g., CNS anomaly, complex congenital heart disease, evidence of metabolic disease, recurrent severe infection, suspected immune deficiency, and multiple malformations). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 202 participants, neuromuscular (45%), respiratory (22%), and immunologic/infectious (18%) were the most commonly observed phenotypes. The diagnostic yield of trio-rapid genome sequencing was higher than that of proband-only clinical exome sequencing (36.6% [95% CI, 30.1-43.7%] vs 20.3% [95% CI, 15.1-26.6%], respectively; p = 0.0004), and the average turnaround time for trio-rapid genome sequencing (median: 7 d) was faster than that of proband-only clinical exome sequencing (median: 20 d) (p < 2.2 × 10-16). The metagenomic analysis identified pathogenic or likely pathogenic microbes in six infants with symptoms of sepsis, and these results guided the antibiotic treatment strategy. Sixteen infants (21.6%) experienced a change in clinical management following trio-rapid genome sequencing diagnosis, and 24 infants (32.4%) were referred to a new subspecialist. CONCLUSIONS: Trio-rapid genome sequencing provided higher diagnostic yield in a shorter period of time in this cohort of critically ill infants compared with proband-only clinical exome sequencing. Precise and fast molecular diagnosis can alter medical management and positively impact patient outcomes.