Next-generation sequencing technologies have been widely applied in diagnosing genetic disorders in pediatric patients. However, the cancer predisposition and tumor characteristics in individuals who have germline pathogenic variants remain unclear. We analyzed exome sequencing data from 75,602 pediatric patients referred for genetic testing between January 2016 and January 2025, tracking cancer as a secondary finding. The most common reasons for genetic testing were symptoms related to the nervous system, metabolic disorders and immune dysfunction. Among 110,692 variants of 139 tumor susceptibility genes, we identified 501 (456 single-nucleotide variants, 45 copy number variations, 0.45%) pathogenic or likely pathogenic (P/LP) and 3,848 (3,650 single-nucleotide variants, 198 copy number variations, 3.5%) variants of uncertain significance leaning toward likely pathogenic variants. Of 411 patients with tumors (203 with preexisting tumors and 208 with new tumors diagnosed during follow-up), 134 (32.6%) harbored causative germline P/LP variants in genes such as NF1 (13.1%), TSC2 (5.8%), RB1 (4.6%) and WT1 (3.2%). Critically, prospective follow-up of 64,187 patients without initial tumors revealed a significantly higher incidence of malignant tumors in those carrying P/LP variants (3.23 per 1,000 person-years) compared with those with variants of uncertain significance leaning toward likely pathogenic or other variants (0.236 and 0.272 per 1,000 person-years, respectively). These findings underscore the importance of proactive genetic counseling and surveillance for pediatric patients with pathogenic germline variants.

X-linked recessive (XR) complete MCTS1 deficiency underlies Mendelian susceptibility to mycobacterial disease (MSMD) in patients with bacille Calmette-Guérin (BCG) disease. We investigated the genotypic and phenotypic landscape of four new unrelated families from four distinct countries. Three patients had adverse reactions to the BCG vaccine, whereas another patient was not vaccinated with BCG and had an infection with Mycobacterium abscessus at 16 years of age. Whole-exome sequencing of the probands revealed hemizygosity for rare germline MCTS1 variants. In addition to a previously reported loss-of-expression (LOE) and loss-of-function (LOF) variant, we identified three new MCTS1 variants. The p.L170* and E60Kfs5* variants are LOF, whereas p.W175* is hypomorphic when overexpressed. Thus, we report four new MSMD patients with complete or partial forms of XR MCTS1 deficiency, including three patients with newly discovered genotypes. A diagnosis of partial or complete XR MCTS1 deficiency should be considered in boys and men with MSMD displaying mycobacterial infection.

Background: Duplications at the 19q13.42 region are rare, and the relationship between 19q13.42 duplications and neurodevelopmental phenotypes remains poorly characterized due to the paucity of cases with well-documented clinical features. Methods: Cases with 19q13.42 duplications were reviewed from a cohort of over seventy-five thousand pediatric patients. These patients, suspected of having genetic diseases, underwent next-generation sequencing (NGS) at two collaborating medical centers between 2016 and December 2024. Cases were identified and subjected to further phenotypic and genomic analysis. The reported cases of 19q13. 42 duplications were also searched in public resources. Results: Twenty patients, including 10 cases from our study and 10 cases from public resources with 19q13.42 duplication were enrolled. The duplication breakpoints detected by NGS in internal cases were nonrecurrent and the duplication sizes ranged from 76.864 to 724.194 Kb, which were verified by quantitative real-time polymerase chain reaction (qPCR). Neurodevelopmental disorders (NDDs) were the primary clinical phenotype, present in 94.1% (16/17) of patients. All 16 cases harbored duplications involving PRKCG, of which 12 contained complete gene duplications and 4 involved partial duplications. Genotypephenotype correlation analysis and the smallest region of overlap (SRO) mapping indicates that PRKCG is a candidate gene underlying the associated NDD phenotypes. Conclusions: We observed recurrent neurodevelopmental features in a subset of reported 19q13.42 duplications and propose PRKCG as a candidate gene warranting follow-up functional studies. These findings provide a preliminary genotype-phenotype framework for this region, though additional cases with comprehensive clinical phenotyping are required to validate and refine these observations.

Reliable genetic testing depends on accurate assessment of sequencing quality in clinically relevant genomic regions that directly influence variant interpretation. We developed TargetQC, a flexible quality control framework that supports user-defined gene sets, coverage thresholds, and variant sets for evaluating sequencing performance across exome sequencing (ES) and genome sequencing (GS) platforms. TargetQC assesses exon and gene coverage, identifies regions meeting predefined coverage thresholds, evaluates variant detection accuracy, and measures sequencing quality at pathogenic variant sites. We applied TargetQC to the reference sample NA12878 and 665 clinical samples across five ES platforms and one GS platform. ES-VendorB and ES-VendorE achieved the most complete coverage of OMIM coding regions in NA12878, whereas ES-VendorD and ES-VendorE showed the highest coverage compliance in clinical samples. ES-VendorB and GS demonstrated the highest variant detection accuracy. TargetQC provides a practical framework for benchmarking sequencing performance and informing platform selection in clinical genomics.

Classic Homocystinuria (HCU) is the second most treatable aminoacidopathy. It affects multiple organs in varying degrees, and early recognition and treatment is crucial to improve the prognosis. Mutations in the CBS gene result in classic HCU, the most common form. Genetic testing is important for the accurate diagnosis of this severe disorder. Case report. A 6-year-old boy presented with high myopia, ectopia lentis, and hypotonia. A brain MRI showed no abnormality, and his electromyogram implicated myogenic damage. His serum homocysteine was 277.5 µmol/L (normal ≤ 15 µmol/L), and methionine was 352.56 µmol/L (normal 0–80 µmol/L); thus, he was diagnosed with classic HCU. Compound heterozygous mutations at two different sites on the cystathionine beta‑synthase (CBS) gene (c.767G > T, c.949 A > G) were identified; the former had not been reported previously. This study reported a novel mutation of CBS gene (c.767G > T). To our knowledge, this is the first report of this novel clinical manifestation of primary hypotonia in homocystinuria patients.

OBJECTIVES:To evaluate the performance of metagenomic next-generation sequencing (mNGS) in detecting pathogens in suspected neonatal sepsis and central nervous system infections. METHODS:This retrospective study included 648 neonates with suspected sepsis or central nervous system infections, with 734 cerebrospinal fluid and 733 blood samples collected. The pathogen spectra detected by mNGS and traditional culture were compared. Using clinical diagnosis as the gold standard, the diagnostic efficacy of the two methods was analyzed. RESULTS:The positive rates of pathogen detection by mNGS in cerebrospinal fluid and blood samples were 15.3% and 40.0%, respectively, significantly higher than those of traditional culture (1.4% and 10.7%, respectively). mNGS identified 25 and 40 distinct pathogenic species from cerebrospinal fluid and blood, respectively, exceeding the 4 and 24 species detected by culture. Ureaplasma, Mycoplasma, and other fastidious pathogens difficult to culture were detected exclusively by mNGS. Using clinical diagnosis as the reference, mNGS showed sensitivities of 50.4% (cerebrospinal fluid) and 46.7% (blood), compared to 5.8% and 18.0% for culture. CONCLUSIONS:mNGS significantly improves pathogen detection rates in neonatal infections compared with traditional culture, provides more comprehensive pathogen information, and holds important clinical value for the precise diagnosis and treatment of neonatal infections.

ObjectiveTo expand the phenotypic and genotypic spectrum of Imagawa-Matsumoto syndrome (IMMAS) by investigating the genetic etiology and unique clinical manifestations of an overgrowth case associated with a SUZ12 gene variant.MethodsWe report a case of IMMAS in an 11-year-old Chinese girl who was admitted to our hospital due to unsteady gait and an abnormal walking pattern for 1.5 years. Trio-based whole-exome sequencing (trio-WES) was performed to identify the genetic etiology. Additionally, we conducted a systematic literature review of previously reported cases of overgrowth syndromes associated with SUZ12 variants.ResultsThe patient presented with generalized overgrowth, characteristic facial features, and skeletal abnormalities consistent with IMMAS. Cervical spine magnetic resonance imaging (MRI) revealed cervical canal stenosis accompanied by signs of cervical spinal cord compression and cord edema. The patient underwent posterior cervical single-door decompression, canal expansion with internal fixation, and adhesiolysis of the spinal cord and nerve roots. Trio-WES identified a de novo variant in SUZ12 (NM_015355.4, c.1783_1786del; p. Lys595Profs*18). The literature review suggested that cervical spinal stenosis in our case may represent a newly reported phenotype associated with SUZ12 variants.ConclusionOur findings expand the phenotypic and genotypic spectrum of IMMAS. For patients with overgrowth syndromes, spinal stenosis should be considered during clinical evaluation.

BACKGROUND:Patients with sitosterolemia (ST) are often misdiagnosed as familial hypercholesterolemia (FH) because of overlapping lipid phenotypes. Sitosterol is considered a disease-specific biomarker; however, its diagnostic utility in highly heterogeneous populations-particularly among children-remains unclear. OBJECTIVE:To evaluate the diagnostic value of phytosterol biomarkers and develop a multivariate model to improve the diagnostic accuracy of ST. METHODS:We conducted a cross-sectional study of 379 children with suspected lipid disorders: ST (n = 38), ABCG5/8 heterozygous carriers (n = 12), genetically confirmed FH (n = 54), individuals with FH-like (n = 50), and healthy controls (n = 225). Clinical characteristics, lipid profiles, phytosterols, liver enzymes, and genetic data were collected. The diagnostic performance of single biomarkers and a multivariate model was evaluated. A clinical gray zone based on sitosterol levels was defined to assess the models' ability. RESULTS:Sitosterol demonstrated near-perfect discrimination for ST in the overall population area under the curve ([AUC] 0.994; 95% CI, 0.988-1.000), outperforming conventional lipid markers. However, substantial overlap in phytosterol distributions was observed among ST, heterozygotes, and FH-related phenotypes. Within the gray zone (sitosterol: 17.7-50 μg/mL), the diagnostic performance of sitosterol declined markedly (AUC 0.653). The multivariable model demonstrated comparable overall performance (AUC 0.983) but significantly improved discrimination in the gray zone (AUC 0.806), with good calibration and greater net clinical benefit. CONCLUSION:Although sitosterol is highly effective for identifying ST, its diagnostic performance declines significantly in clinically significant gray zone cases. A combined sterol-based model improves diagnostic discrimination in these challenging scenarios and supports a stepwise diagnostic strategy for children with suspected ST.

The 15q26 deletion and duplication syndromes are rare chromosome diseases with growth deviation and structural anomalies such as facial abnormality, cardiac malformation and hand/foot/skeleton malformations. Insulin-like growth factor 1 receptor (IGF1R), located on chromosome 15q26, is key for pre- and postnatal growth. The present study aimed to determine whether IGF1R serves as a key factor in growth regulation in 15q26 deletion and duplication syndromes. Patients with 15q26 deletions and duplications enrolled in the China Neonatal Genomes Project (CNGP) were recruited. A systematic review of 15q26 deletion and duplication cases was performed, followed by meta-analysis to evaluate the roles of IGF1R and three other genes [myocyte enhancer factor 2A (MEF2A), leucine-rich repeat kinase 1 (LRRK1) and nuclear receptor subfamily 2 group F member 2] involved in growth regulation. A total of 10 eligible patients from the CNGP, including seven with deletions and three with duplications, were identified. The literature search and screening yielded 78 patients with 15q26 deletions and 10 with 15q26 duplications. Clinical features observed in >70% of the patients in the deletion group were facial abnormalities, developmental delay, short stature and hand/foot/skeleton malformations, whereas the duplication group exhibited facial abnormality, hand/foot/skeleton malformation and speech development delay. In 15q26 deletion, three candidate genes were associated with an increased risk of short stature: IGF1R [odds ratio (OR): 8.43; 95% confidence interval (CI): 2.22-32.00], LRRK1 (OR: 100.00; 95% CI: 11.86-843.23) and MEF2A (OR: 32.21; 95% CI: 3.81-272.47). In 15q26 duplication, none of the candidate genes significantly affected tall stature. Using meta-analysis, the present study revealed that IGF1R is not the only key gene responsible for growth abnormalities in 15q26 deletion and duplication syndromes.

Background: Early identification of severe unconjugated hyperbilirubinemia is critical to prevent bilirubin encephalopathy and long-term neurological damage. The etiology of neonatal jaundice is complex. This study aims to identify genetic variants associated with severe neonatal jaundice (SNJ) through a genomewide association approach and to evaluate their potential for risk prediction. Methods: We conducted a genome-wide association study using whole-exome sequencing data from 155 SNJ cases and 160 controls without SNJ. Genetic and clinical variables were integrated using a LASSObased machine learning approach to assess their importance in classifying SNJ. Causal inference methods were applied to evaluate the relationship between identified single-nucleotide polymorphisms (SNPs) and SNJ. Results: In our cohort, SNJ was associated with increased erythrocyte count and hemoglobin (Hb) concentration. A positive correlation between erythrocyte count and Hb was also observed. Seventeen SNPs were found to be significantly associated with total blood erythrocyte count. A missense mutation in the gene haptoglobin-related protein (HPR), rs144648182, was enriched in SNJ. This mutation may affect the ability of HPR to bind free Hb, and a machine learning causal inference approach confirmed the potential causal effect of rs144648182 with serum total bilirubin. Nine genotypes and clinical phenotypes associated with SNJ were identified by the LASSO method and used to construct a clinical prediction model for SNJ, which enables accurate prediction of high-risk individuals in neonatal jaundice and aids clinical decisions. Conclusions: We applied machine learning causal inference to GWAS data and identified potential erythroid-related genetic factors, including the HPR variant rs144648182, that may contribute to SNJ. This finding represents a testable hypothesis requiring experimental validation. A prediction model based on genetic and clinical variables demonstrated potential for risk stratification among jaundiced neonates, though external validation is needed before clinical application.

BACKGROUND:Feeding difficulties significantly impact neonatal well-being. This study explores the clinical characteristics, etiologies, and diagnostic practices for full-term neonates with feeding difficulties in neonatal intensive care units (NICUs). METHODS:This retrospective cohort study recruited full-term infants admitted to NICUs participating in the China Neonatal Genome Project from March 2017 to December 2021, diagnosed with feeding difficulties persisting >72 h. RESULTS:Among 220 patients, the most common symptoms were poor sucking (39.5%), vomiting (22.3%), and dysphagia (14.1%). High-yield diagnostic modalities included genetic tests (83/220, 37.3%), brain imaging (70/145, 48.3%), laryngoscopy (47/54, 87.0%), and muscle biopsy (12/28, 42.9%). A definitive etiology was identified through clinical evaluation in 100 cases (45.5%), 48 of which (21.8%) were subsequently confirmed by genetic testing. In an additional 35 cases (15.9%), genetic results contributed to diagnostic clarification or revision. Compared to neonates without genetic disorders, the 83 patients with genetic disorders were more likely to have persistent feeding difficulties, reduced muscle tone, craniofacial deformities, urinary and reproductive system malformations, and a need for invasive respiratory support (P < 0.05 for all). CONCLUSION:Identifiable etiologies were found in over 60% cases, with genetic disorders representing a significant subset. Selective genetic testing and targeted diagnostic strategies are essential for managing feeding difficulties in this vulnerable population. IMPACT:Feeding difficulties in full-term neonates admitted to NICUs remain under-recognized compared to those in preterm infants. This study provides a comprehensive overview of their clinical features and underlying etiologies, highlighting a substantial proportion with identifiable causes, including genetic and non-genetic factors (e.g., neuromuscular and gastrointestinal). By outlining the diagnostic yield of key modalities and their clinical relevance, our findings offer practical guidance for early evaluation of feeding difficulties in this vulnerable population.

Next generation sequencing (NGS) technology is playing an increasingly important role in the diagnosis of genetic diseases. Whole exome sequencing (WES) which targets the coding regions of the genome has been widely used in the diagnosis of genetic diseases for its low cost and high efficiency. However, compared to conventional methods, the NGS process is intricate, and there is variability in the expertise of data analysts and variant interpreters, which may lead to inconsistencies in the outcomes. To ensure the quality of testing and enhance the diagnostic rate of diseases, this consensus has provided recommendations regarding the laboratory setup, operational procedures, data analysis, result interpretation, and quality control for WES, with an aim to standardize its application in the detection of genetic disorders.

In East Asia, IL10RA is the predominant pathogenic gene in patients with very early-onset inflammatory bowel disease (VEO-IBD), frequently characterised by refractory diarrhoea and severe perianal disease, resulting in elevated death rates. IL10RA-deficient IBD, an autosomal recessive genetic disorder, has been documented to be inherited through the conventional compound heterozygous or homozygous mutation patterns from both parents. We present two cases with apparent homozygosity resulting from distinct causes, both of which seem homozygous on the genetic map. Further investigation reveals that detecting hidden genetic patterns is essential for accurate diagnosis, genetic counselling, and disease mechanism analysis. Peripheral blood samples were collected from two patients and their parents. Whole-exome sequencing (WES), Sanger sequencing, Comparative genomic hybridisation (CGH) and SNP array, Capture-based CNV (CapCNV) analysis, and real-time quantitative PCR (qPCR) were employed to investigate the genetic mechanisms and variants within the families. Both patients were followed up, and descriptive analyses were performed to characterise their clinical phenotypes, biochemical parameters, endoscopic findings, and intestinal histopathology. Multiple databases were systematically searched to review all cases of IBD with large IL10RA deletions. Two families underwent WES, and a homozygous mutation was identified in the IL10RA gene on chromosome 11 in both families. In patient 1, pedigree analysis, CGH and SNP 4 × 180 K microarray testing identified paternal uniparental diploidy (c.301C > T/11q12.3-11q25del) [upd (11) pat] on chromosome 11. Patient 2 had compound heterozygosity (c. 299 T > G/exon2_3del), comprising a point mutation and an overlapping exon deletion mutation in IL10RA, as determined using familial analysis, Sanger sequencing, CapCNV analysis, and qPCR validation. In addition, the study systematically reviewed 15 cases of IBD patients with large deletions in the IL10RA gene from the literature. This is the first description of two cases of apparent homozygosity in IL10RA. This report emphasizes the importance of optimizing the genetic analysis workflow, especially when there is doubt about the initial whole exome sequencing results.

RelA deficiency resulting from mutations in the human RELA gene is a recently identified inborn errors of immunity (IEI). The RELA gene encodes the RelA (p65) protein, one of the five transcription factors of the NF-κB family, which plays a critical role in the regulation of transcriptional programs essential for the development and maintenance of the immune system, skeletal system, and epithelial tissues. RelA deficiency is classified as RelA haploinsufficiency and RelA dominant-negative. The mainly pathogenesis is that impaired NF-κB activation in fibroblasts, which leads to the downregulation of NF-κB-dependent antiapoptotic protein expression and cytokine transcription, renders fibroblasts susceptible to TNF-induced apoptosis. Clinical manifestations of RelA deficiency are typically characterized by recurrent oral ulcers or Behçet’s disease-like manifestations. Since the first report in 2016, only a few dozen cases of RelA deficiency have been documented worldwide. Treatment strategies have not been standardized, with current mainstream approaches primarily involving immunosuppressive therapies, including TNF inhibitors or glucocorticoids. In this study, we report the clinical phenotypes of three patients with RelA deficiency from two families, along with one novel pathogenic mutation (c.1166_1184del, p.Q389fs) in the RELA gene. This expands the spectrum of pathogenic mutations associated with the RELA gene and clinical manifestations of RelA deficiency. Additionally, we provide a comprehensive summary of the genetic phenotypes, clinical characteristics, and treatment strategies of all previously reported cases of RelA deficiency. Our aim is to increase awareness of this rare IEI and to offer insights that may guide its treatment.

Genome sequencing (GS) refers to a technology that comprehensively and systematically detects the DNA sequences of an individual's nuclear and mitochondrial genomes. It aims to identify genetic variants and investigate their roles in human health and disease progression. As an emerging diagnostic tool, GS offers significant support for clinical diagnosis due to its high throughput, accuracy, and comprehensiveness. However, the complexity of data analysis and interpretation requires substantial professional expertise and experience, posing considerable challenges. When applying GS technology for molecular diagnosis of genetic diseases, ethical and technical issues related to clinical application arise, including informed consent, diagnostic data interpretation, and defining the scope and content of clinical reports. This expert consensus outlines the core workflow of clinical genome sequencing (cGS), clarifies its testing scope and technical limitations, and provides key steps for data quality control, analysis, annotation, and variant interpretation. It also addresses controversial issues related to report content and informed consent. This consensus aims to assist professionals in accurately understanding and appropriately utilizing clinical genome sequencing, thereby improving diagnostic accuracy for genetic diseases, enhancing the clinical utility of the technology, and advancing medical scientific research.

Chromosome 17p13.3 is a region of genomic instability associated with different neurodevelopmental diseases. The malformation spectrum of 17p13.3 microdeletions ranges from an isolated lissencephaly sequence to Miller-Dieker syndrome, while 17p13.3 microduplications result in autism, learning disabilities, microcephaly and other brain malformations. This study aims to provide a more comprehensive delineation of the clinical and genetic characteristics associated with 17p13.3 alterations. We retrospectively analyzed the next-generation sequencing (NGS) data of more than 40 thousand patients from January 2016 to December 2021 and identified 38 pediatric patients with copy-number variations (CNVs) or single-nucleotide variations (SNVs) in 17p13.3 region. Published patients with CNVs in the 17p13.3 region were also collected and we performed a Chi-square test to compare the phenotype spectrum of microdeletions and microduplications. Among the 27 CNV patients, 20 patients with microdeletions and 7 patients with microduplications were found. PAFAH1B1 was the most frequently deleted gene and CRK was the most frequently duplicated gene. Affected genes in 11 SNV patients included PAFAH1B1 and PRPF8. Developmental delay was the most common abnormality detected in the 38 patients (29/38, 76.3

FAS gene defects lead to autoimmune lymphoproliferative syndrome (ALPS), which is often inherited in an autosomal dominant and rarely in an autosomal recessive manner. We report a case of a newborn girl with novel compound heterozygous variants in FAS and reveal the underlying mechanism. Whole-exome sequencing (WES) was used to identify pathogenic variants. Multiparametric flow cytometry analysis, phosflow analysis, and FAS-induced apoptosis assays were used to explore the effects of the variants on FAS expression, apoptosis, and immunophenotype. The HEK293T cells were used to assess the impact of the variants on protein expression and FAS-induced apoptosis. The patient was born with hepatosplenomegaly, anemia, and thrombocytopenia. She also experienced COVID-19, rotavirus infection, herpes simplex virus infection, and severe pneumonia. The proportion of double-negative T cells (DNTs) was significantly elevated. Novel FAS compound heterozygous variants c.310T > A (p.C104S) and c.702_704del (p.T235del) were identified. The apoptotic ability of T cells was defective, and FAS expression on the surface of T cells was deficient. The T235del variant decreased FAS expression, and the C104S protein remained in the endoplasmic reticulum (ER) and could not translocate to the cell surface. Both mutations resulted in loss-of-function in terms of FAS-induced apoptosis in HEK293T cells. The DNTs were mainly terminally differentiated T (TEMRA) and CD45RA+HLA-DR+, with high expression of CD85j, PD-1, and CD57. The percentage of Th1, Tfh, and autoreactive B cells were significantly increased in the patient. The abnormal immunophenotyping was partially attenuated by sirolimus treatment. We identified two variants that significantly affect FAS expression or localization, leading to early disease onset of in the fetus. Abnormalities in the mTOR pathway are associated with a favorable response to sirolimus.

ObjectiveFructose-1,6-bisphosphatase deficiency (FBP1D) is a rare inborn error due to mutations in the FBP1 gene. The genetic spectrum of FBP1D in China is unknown, also nonspecific manifestations confuse disease diagnosis. We systematically estimated the FBP1D prevalence in Chinese and explored genotype-phenotype association.MethodsWe collected 101 FBP1 variants from our cohort and public resources, and manually curated pathogenicity of these variants. Ninety-seven pathogenic or likely pathogenic variants were used in our cohort to estimate Chinese FBP1D prevalence by three methods: 1) carrier frequency, 2) permutation and combination, 3) Bayesian framework. Allele frequencies (AFs) of these variants in our cohort, China Metabolic Analytics Project (ChinaMAP) and gnomAD were compared to reveal the different hotspots in Chinese and other populations. Clinical and genetic information of 122 FBP1D patients from our cohort and published literature were collected to analyze the genotype-phenotypes association. Phenotypes of 68 hereditary fructose intolerance (HFI) patients from our previous study were used to compare the phenotypic differences between these two fructose metabolism diseases.ResultsThe estimated Chinese FBP1D prevalence was 1/1,310,034. In the Chinese population, c.490G>A and c.355G>A had significantly higher AFs than in the non-Finland European population, and c.841G>A had significantly lower AF value than in the South Asian population (all p values < 0.05). The genotype-phenotype association analyses showed that patients carrying homozygous c.841G>A were more likely to present increased urinary glycerol, carrying two CNVs (especially homozygous exon1 deletion) were often with hepatic steatosis, carrying compound heterozygous variants were usually with lethargy, and carrying homozygous variants were usually with ketosis and hepatic steatosis (all p values < 0.05). By comparing to phenotypes of HFI patients, FBP1D patients were more likely to present hypoglycemia, metabolic acidosis, and seizures (all p-value < 0.05).ConclusionThe prevalence of FBP1D in the Chinese population is extremely low. Genetic sequencing could effectively help to diagnose FBP1D.

Objective: We aimed to investigate the clinical and genetic risk factors associated with neonatal severe unconjugated hyperbilirubinemia.Methods: This was a retrospective, 1:1 matched, case–control study. We included 614 neonates diagnosed with severe unconjugated hyperbilirubinemia (serum total bilirubin level ≥425 μmol/L or serum total bilirubin concentration that met exchange transfusion criteria) from the China Neonatal Genomes Project in Children’s Hospital of Fudan University. Clinical exome sequencing data were analyzed using a data analysis pipeline of Children’s Hospital of Fudan University. The factors associated with severe unconjugated hyperbilirubinemia were assessed using univariable and multivariable logistic regression analyses. Interaction analyses were examined between clinical and genetic risk factors.Results: ABO/Rh incompatibility hemolysis (odds ratio [OR] 3.36, 95% confidence interval [CI] 2.32–4.86), extravascular hemorrhage (OR 2.95, 95% CI 2.24–3.89), weight loss (OR 5.46, 95% CI 2.88–10.36), exclusive breastmilk feeding (OR 3.56, 95% CI 2.71–4.68), and the homozygous mutant of UGT1A1 211G>A (OR 2.35, 95% CI 1.54–3.59) were all identified as factors significantly associated with severe unconjugated hyperbilirubinemia. The presence of UGT1A1 211G>A mildly increased the risk of severe unconjugated hyperbilirubinemia caused by ABO/Rh incompatibility hemolysis (OR 3.98, 95% CI 2.19–7.23), although the effect is not statistically significant.Conclusion: ABO/Rh incompatibility hemolysis, extravascular hemorrhage, weight loss, exclusive breastmilk feeding, and the homozygous mutant of UGT1A1 211G>A were found to be risk factors for severe unconjugated hyperbilirubinemia. Clinical factors remain the most crucial and preventable determinants in managing severe unconjugated hyperbilirubinemia, with a minimal genetic contribution. The establishment of preconception care practices and the reinforcement of screening for the aforementioned risk factors are essential steps for preventing severe unconjugated hyperbilirubinemia.