OBJECTIVE: To investigate the current status of clinical genetics specialization development and the diagnostic and therapeutic capabilities for hereditary diseases across medical institutions in Shanghai, and to assess the necessity and feasibility of establishing training bases for clinical genetics specialists. METHODS: By employing a cross-sectional survey design, the Clinical Genetics Committee of Shanghai Medical Association has conducted questionnaire surveys from March to April 2025 across 54 healthcare institutions in Shanghai (including 33 tertiary hospitals and 21 secondary hospitals). The survey involved administrative departments and medical personnel from 15 clinical specialties. The survey has covered current genetic disease diagnosis and treatment practices, relevant and specialised disease types, genetic department establishment, testing capabilities, personnel teams, and training requirements. RESULTS: The results revealed that 78.0% of clinical departments surveyed had treated patients with hereditary disorders. Shanghai possesses diagnostic and therapeutic expertise for over 95% of hereditary diseases listed in its rare disease catalogue, reflecting both the practical clinical demand for such conditions and the city's overall diagnostic and therapeutic strengths in this field. Nevertheless, significant disparities exist in the development of genetics departments across different tiers of healthcare institutions. Resources for genetic testing capabilities (including molecular, cellular, and biochemical testing) are also unevenly distributed across different tiers of hospitals. The survey further revealed that only 26.0% of departments believe that their current physician structure fully meets the diagnostic and treatment demands. Over 90% of departments consider standard training for clinical genetic specialists necessary, with 74.0% expressing willingness to participate in establishing training bases. Based on above findings and thorough deliberation, the Clinical Genetics Committee of the Shanghai Medical Association proposes advancing specialist training and discipline development through establishing a standard training system. The committee has drafted a three-year training protocol featuring a "joint training"-centered model, recommending a pilot-first, dynamically optimized strategy for steadily advancing training base development. CONCLUSION Shanghai faces substantial demand for genetic disease diagnosis and treatment, yet exhibits shortcomings in clinical genetics specialization development, resource allocation, and talent pipeline cultivation. To establish a standard training system holds significant practical importance and is underpinned by a broad demand.
Humans ; China ; Surveys and Questionnaires ; Genetic Diseases, Inborn/genetics* ; Cross-Sectional Studies ; Genetics, Medical/education* ; Genetic Testing

OBJECTIVE: To elucidate the epidemiological characteristics and genetic variant profile of Short-chain acyl-CoA dehydrogenase deficiency (SCADD) among newborns from Hainan Province and evaluate its significance within the local neonatal disease screening panel. METHODS: A total of 84 184 newborns born in Hainan Province from February to December 2024 were included. Tandem mass spectrometry (MS/MS) was employed to detect butyrylcarnitine (C4) and propionylcarnitine (C3) levels in dried blood spots. Screening thresholds were set at C4 > 0.43 μ mol/L and C4/C3 ratio > 0.28. Suspected cases underwent confirmatory testing via urinary ethylmalonic acid analysis by gas chromatography-mass spectrometry and whole-exome sequencing for ACADS gene variants. This study was approved by the Medial Ethics Committee of the hospital (Ethics No.: HNWCMC-2024-55). RESULTS: Six SCADD cases (male-to-female ratio = 1:1) were diagnosed, with all carrying compound heterozygous variants at two loci, yielding a prevalence of 7.13 per 100,000 live births. Four known ACADS gene variants were identified, with both c.322G>A and c.625G>A detected at a frequency of 41.7%. Regular follow-up (as of January 2026) revealed that all diagnosed cases have remained asymptomatic with normal growth and development. CONCLUSION The prevalence of SCADD among newborns in Hainan Province is relatively high, with c.322G>A and c.625G>A as the hotspot variants in the region. Given the absence of clinical phenotypes in all screen-detected cases during long-term follow-up, it is recommended to remove this condition from the routine neonatal screening program for this region to reduce unnecessary anxiety and medical cost.
Humans ; Infant, Newborn ; Neonatal Screening/methods* ; Female ; Male ; Lipid Metabolism, Inborn Errors/epidemiology* ; Acyl-CoA Dehydrogenase/genetics* ; China/epidemiology* ; Follow-Up Studies

Case 1: A 19-day-old male infant presented with poor feeding and decreased activity for 2 weeks, worsening with poor responsiveness for 3 days. At 5 days old, he developed poor feeding and poor responsiveness, was hospitalized, and was found to have elevated blood ammonia and thrombocytopenia. Whole-genome genetic analysis revealed a pathogenic homozygous mutation in the PCCA gene, NM-000282.4: c.1834-1835del (p.Arg612AspfsTer44), leading to a diagnosis of propionic acidemia. Case 2: A 4-day-old male infant presented with poor responsiveness and feeding difficulties since birth, with elevated blood ammonia for 1 day. He showed weak sucking and deteriorating responsiveness, with blood ammonia >200 µmol/L. Genetic testing identified two heterozygous mutations in the MMUT gene: NM_000255.4: c.1677-1G>A and NM_000255.4: ex.5del, confirming methylmalonic acidemia. Case 3: A 20-day-old male infant presented with poor feeding for 15 days and skin petechiae for 8 days. He developed feeding difficulties at 5 days old and lower limb petechiae at 12 days old, with blood ammonia measured at 551.6 µmol/L. Genetic analysis found two heterozygous mutations in the PCCA gene: NM_000282.4: c.1118T>A (p.Met373Lys) and NM_000282.4: ex.16-18del, confirming propionic acidemia. In the first two cases, continuous hemodiafiltration was performed for 30 hours and 20 hours, respectively, before administering carglumic acid. In the third case, carglumic acid was administered orally without continuous hemodiafiltration, resulting in a decrease in blood ammonia from 551.6 µmol/L to 72.0 µmol/L within 6 hours, with a reduction rate of approximately 20-25 µmol/(kg·h), similar to the first two cases. Carglumic acid was effective in all three cases, suggesting it may help optimize future treatment protocols for organic acidemia.
Humans ; Male ; Infant, Newborn ; Propionic Acidemia/drug therapy* ; Amino Acid Metabolism, Inborn Errors/genetics* ; Mutation ; Methylmalonyl-CoA Decarboxylase/genetics* ; Citrates/administration & dosage* ; Carbon-Carbon Ligases/genetics* ; Glutamates

OBJECTIVES: To develop a quality control indicator system for neonatal screening of inherited metabolic diseases in obstetric settings, so as to provide a standardized tool for quality control in clinical neonatal screening of inherited metabolic diseases. METHODS: From March to May 2024, a literature review combined with expert clinical experience was conducted to develop a preliminary questionnaire on quality control indicators for neonatal screening of inherited metabolic diseases. The final indicator system was established after two rounds of the Delphi method, and the Analytic Hierarchy Process was used to determine indicator weights. RESULTS: Sixteen questionnaires were distributed in each of the two consultation rounds, with a valid response rate of 100% for both. The expert authority coefficients were 0.863 and 0.876, respectively. Kendall's coefficient of concordance for the importance and feasibility of the indicators ranged from 0.091 to 0.125. The final indicator system comprised 3 primary indicators, 8 secondary indicators, and 28 tertiary indicators for neonatal screening of inherited metabolic diseases in obstetric settings. CONCLUSIONS The quality control indicator system developed using the Delphi method demonstrates a strong systematic structure, high clinical adaptability, and strong operability, and can be effectively applied to quality control in neonatal screening of inherited metabolic diseases in obstetric settings.
Humans ; Infant, Newborn ; Neonatal Screening/standards* ; Quality Control ; Metabolism, Inborn Errors/diagnosis* ; Metabolic Diseases/diagnosis* ; Delphi Technique ; Female ; Quality Indicators, Health Care ; Pregnancy

OBJECTIVE: To explore the results of four types of Urea cycle disorders (UCDs) in newborns from the Xuzhou region, assess the efficacy of newborn screening by tandem mass spectrometry (MS/MS), and analyze their genetic characteristics. METHODS: A retrospective analysis was performed using tandem mass spectrometry to screen for inherited metabolic disorders in 691 712 newborns at the Maternal and Child Health Care Hospital of Xuzhou from November 2015 to December 2023. Ten children (cases 1-10) were diagnosed with Ornithine transcarbamylase deficiency (OTCD), Carbamoylphosphate synthase 1 deficiency (CPS1D), Arginase deficiency (ARGD), and Argininosuccinate synthase deficiency (ASSD) based on MS/MS and genetic testing. This study was approved by the Medical Ethics Committee of Xuzhou Maternity and Child Health Care Hospital (Ethics No.XZFY2024-051K-01J). RESULTS: A total of 691 712 neonates were screened for UCDs using MS/MS, which identified 1 237, 1 237, 510, and 1 009 initial positive cases for OTCD, CPS1D, ASSD, and ARGD, respectively. After genetic testing, 1 case of OTCD, 1 case of CPS1D, 1 case of ASSD, and 7 cases of ARGD were confirmed. The overall positive predictive value for these four UCDs was 0.362%. Among the 10 diagnosed UCD cases, four novel variants were identified, which included OTC: c.1024C>A (p.L342M) and ASS1: c.826A>G (p.M276V), c.695C>T (p.P232L) and c.694C>T (p.P232S). Bioinformatic analysis has rated these as variants of uncertain clinical significance or likely pathogenic based on guidelines from the American College of Medical Genetics and Genomics (ACMG). CONCLUSION The incidence of four UCDs in neonates from the Xuzhou area is relatively low, and there is a correlation between genetic variants and clinical phenotypes. For novel variants with uncertain clinical significance or suspected pathogenicity, their pathogenicity should be clarified in conjunction with clinical and biochemical indicators. The four novel pathogenic variants of UCDs identified in this study have enriched the mutational spectrum of UCDs-associated genes in the Xuzhou region.
Humans ; Infant, Newborn ; Tandem Mass Spectrometry/methods* ; Urea Cycle Disorders, Inborn/diagnosis* ; Neonatal Screening/methods* ; Genetic Testing/methods* ; Female ; Retrospective Studies ; Male ; Ornithine Carbamoyltransferase Deficiency Disease/diagnosis* ; Mutation ; Carbamoyl-Phosphate Synthase (Ammonia)/genetics* ; Ornithine Carbamoyltransferase/genetics*

Next generation sequencing (NGS) technologies, including whole exome sequencing (WES) and whole genome sequencing (WGS), have greatly increased the diagnostic rates for genetic disorders. However, challenges still remain with the interpretation of variants of uncertain significance (VUS), variants in non-coding regions, and understanding of the effects of such variants on downstream genes. As a result, the diagnostic rates have typically ranged from 25% to 57%. RNA sequencing (RNA-seq) can complement DNA sequencing by revealing the functional consequences of genetic variants through the detection of aberrant gene expression, abnormal splicing events, allele-specific expression, and fusion gene expression. This has further increased the diagnostic rate of genetic disorders and enriched their therapeutic strategies. By broadening the scope of conventional genomic diagnostic methods, RNA-seq is poised to become a novel tool for the diagnosis of genetic disorders. This review has explored the methodologies and technical characteristics of RNA-seq by focusing on its recent advancement in clinical diagnosis, applications in undiagnosed genetic disorders, and the main challenges encountered.
Humans ; Genetic Diseases, Inborn/genetics* ; High-Throughput Nucleotide Sequencing/methods* ; Sequence Analysis, RNA/methods* ; Exome Sequencing/methods*

OBJECTIVE: To elucidate the clinical and genetic characteristics of familial cases with Glucose transporter type 1 deficiency syndrome (Glut1DS). METHODS: A survey of family history was conducted on children (proband) with Glut1DS who had visited Peking University First Hospital between November 2008 and April 2024 by focusing on the clinical manifestations of family members. Peripheral venous blood (2 mL) was collected from the pediatric patients and their parents. Genomic DNA was extracted and sequenced subsequently. Sanger sequencing was performed to validate the identified variant sites of the SLC2A1 gene in the probands and their family members. The pathogenicity of suspected variants was analyzed according to the 2015 American College of Medical Genetics and Genomics (ACMG) Standards and Guidelines for the Interpretation of Sequence Variants. The clinical features, auxiliary examinations, and mutational characteristics of family members with SLC2A1 variants were analyzed. This study has been approved by the Clinical Research Ethics Committee of Peking University First Hospital (Ethics No. 2021 Research 332). RESULTS: Among 87 cases with Glut1DS, 10 families with autosomal dominate inherited cases were identified, accounting for 11.0% of the cases. Of the 11 children, 8 were boys and 3 were girls. The onset of the disease had ranged from 3 months to 120 months (median 6 months), with 4 cases of early-onset classic type, 2 cases of late-onset classic type, and 5 cases of non-classic type. Six children had seizures, and 7 exhibited movement disorders. Seven children underwent developmental assessment, of which 3 had mild developmental delay, 2 were borderline, and 2 were normal. Nine children underwent lumbar puncture. The cerebrospinal fluid glucose levels ranged from 1.45 to 2.25 mmol/L (median 1.86 mmol/L), and the cerebrospinal fluid to blood glucose ratios ranged from 0.29 to 0.44 (median 0.35). Among the 8 fathers with SLC2A1 gene variants, 4 were asymptomatic, 2 developed paroxysmal exercise-induced movement disorders (PED) in childhood and adulthood, respectively. 1 had poor memory since childhood, 1 developed migraines during adolescence, and his sister was an asymptomatic carrier. The father with childhood-onset PED had a cerebrospinal fluid test with CSF glucose of 1.85 mmol/L. Of the 3 mothers with SLC2A1 gene mutations, 1 was an asymptomatic carrier; 2 developed PED in childhood and after the age of 20, respectively. The mother who developed PED in childhood also had psychomotor developmental delay. Genetic testing results revealed that among 10 families, 8 carried missense variants, 1 carried a nonsense variant, and 1 carried a small fragment insertion leading to a frameshift variant. Among the 11 cases, SLC2A1 gene variants in 8 children were inherited from their fathers, while in 3 cases, the variants were inherited from their mothers. The pathogenicity of the genetic variants was evaluated according to the Standards and Guidelines for the Interpretation of Sequence Variants published by the ACMG. Among the 8 variants identified in the 10 families, 4 were classified as pathogenic variants, 1 as likely pathogenic, and 3 as variants of uncertain significance (VUS). Four variant sites, including c.204_205insTCTC (p.V69fs), c.412G>C (p.G138R), c.431T>G (p.V144G), and c.875A>G (p.Y292C), were not previously reported in the literature. Among these, the latter three were categorized as VUS. CONCLUSION Familial Glut1DS account for 11.0% of the cases in China, with the majority of SLC2A1 gene variants inherited from the fathers, predominantly missense mutations, and with an autosomal dominant inheritance pattern. Probands tend to have earlier onset and more severe symptoms than their parents, who often present with mild or no symptoms.
Humans ; Male ; Female ; Glucose Transporter Type 1/deficiency* ; Monosaccharide Transport Proteins/deficiency* ; Child ; Child, Preschool ; Carbohydrate Metabolism, Inborn Errors/genetics* ; Mutation ; Infant ; Pedigree ; Adolescent ; Adult

OBJECTIVE: To assess the value of whole exome sequencing (WES) for the diagnosis of early-onset genetic diseases among infants aged 0 to 6 month in Ningbo region. METHODS: 268 infants presented at the Women and Children's Hospital Affiliated to Ningbo University from January 2022 to June 2024 undergoing WES-based genetic testing were enrolled. Peripheral blood samples were collected from the infants and their parents and subjected to WES. Pathogenic variants were identified by clinical manifestations. This study has been approved by the Medical Ethics Committee of the Hospital (Ethics No. EC2023-017). RESULTS: Among the 268 infants, 124 (46.3%) had phenotype-explaining genetic variants. For 42 family-based WES tests, 20 (47.62%) were abnormal, whilst in 226 single-person WES tests, 104 (46.02%) had abnormalities, with 76 (33.63%) verified by parental testing. In 96 fully family-verified cases, 31 were de novo, 40 were parent-inherited, 25 were single-parent-inherited. These included 35 inborn metabolic errors, 28 rare syndromes, 9 neurodevelopmental disorders, 4 musculoskeletal diseases, 5 congenital deafness, 2 mitochondrial diseases, 4 endocrine diseases, and 9 others. Among these, there were 7 pathogenic copy number variations (all deletions), 3 chromosomal abnormalities, and 85 single-nucleotide variations. One case of Beckwith-Wiedemann syndrome was detected by methylation MLPA. Among the single-nucleotide variants, 114 pathogenic/likely pathogenic variants were identified in 61 genes, with common ones including missense variants (64.04%), frameshifting variants (20.18%) and splicing variants (4.39%). CONCLUSION WES can offer effective diagnosis for hereditary diseases with specific/non-specific manifestations. For early-age infants, higher detection rates may be attained for inborn metabolic errors, rare syndromes, neurodevelopmental disorders, congenital deafness, and musculoskeletal diseases. Compared with single-person WES, family-based WES can attain a higher diagnostic efficiency.
Humans ; Exome Sequencing/methods* ; Infant ; Female ; Male ; Infant, Newborn ; Genetic Diseases, Inborn/diagnosis* ; Genetic Testing/methods*

OBJECTIVE: To explore the incidence, clinical features, genetic variant characteristics and prognosis of Glutaric acidemia type I (GA1) among neonates from Henan Province. METHODS: A total of 814 625 neonates undergoing screening for inherited metabolic diseases by tandem mass spectrometry (MS/MS) at the Third Affiliated Hospital of Zhengzhou University from January 2016 to December 2022 were selected as the study subjects. A retrospective method was adopted to collect the clinical data of the patients. Whole exome sequencing was carried out to detect GCDH gene variants in individuals with positive results by GA1 newborn screening, and Sanger sequencing was used to verify the candidate variants. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the pathogenicity of candidate variants was rated. This study was approved by the Medical Ethics Committee of the Hospital (Ethics Number: 2019 Medical Ethics Review No. 67). RESULTS: Eight cases of GA1 were diagnosed among the 814 625 neonates. Blood glutaryl carnitine (C5DC) and urine glutaric acid (GA) levels of the 8 children were higher than the normal reference values. In total 12 variants were detected, all of which were missense variants. c.1064G>A (p.Arg355His) was the most common one, accounting for 21.4% (3/14). Three GCDH gene variants, including 1297G>C (p.Ala433Pro), c.467G>A (p.Gly156Asp) and c.1125T>G (p.Cys375Trp), were previously unreported. REVEL software analysis predicted that all of the three variants were harmful. 3D protein structure modeling indicated that the three variants may cause amino acid residue alterations, and c.1297G>C (p.Ala433Pro) and c.1125T>G (p.Cys375Trp) may result in increase in hydrogen bonds and affect the function of GCDH protein. By December 2023, one of the eight children had deceased, and another child had severe clinical symptoms with poor prognosis. Six children had a good prognosis, of which two had mild motor development delay and four had normal development without clinical symptoms. CONCLUSION The incidence of GA1 in newborns screened by MS/MS in Henan Province is 1/101 828, and the carrier rate of pathogenic GCDH variants is 1/160. The c.1064G>A (p.Arg355His) may be the hotspot variant of the GCDH gene among children with GA1 in Henan. Discovery of the three novel variants has enriched the mutational spectrum of the GCDH gene and provide a basis for the early diagnosis, treatment, prognosis and genetic counseling of this disease.
Humans ; Amino Acid Metabolism, Inborn Errors/epidemiology* ; Glutaryl-CoA Dehydrogenase/chemistry* ; Infant, Newborn ; Female ; Neonatal Screening/methods* ; Male ; Brain Diseases, Metabolic/epidemiology* ; China/epidemiology* ; Retrospective Studies ; Mutation ; Genetic Variation ; Glutarates

OBJECTIVE: To explore the genetic basis of a child with Chanarin-Dorfman syndrome (CDS) manifesting as ichthyosis. METHODS: A child who had presented at Henan Provincial People's Hospital in June 2023 was selected as study subject. Clinical data of the child was collected. Peripheral blood samples were collected from the child and her parents. Following extraction of genomic DNA, whole-exome sequencing (WES) was carried out. Candidate variants were verified by Sanger sequencing. Relevant literature was searched in databases using key words "Chanarin-Dorfman syndrome" and "ABHD5 gene". The clinical manifestations and variant sites of previously reported cases were compiled and analyzed for correlations. This study was approved by the Medical Ethics Committee of Henan Provincial People's Hospital [Ethics No.: (2019) Jun Shen No. (134)]. RESULTS: WES revealed that the child has harbored compound heterozygous variants of the ABHD5 gene, namely c.99_103del (p.H34*) in exon 2 and c.770C>G (p.P257R) in exon 5, which were inherited from her father and mother, respectively. Bioinformatic analysis suggested that both variants were pathogenic. Literature review indicated that the affected organs in CDS are ranked from most to least including liver, eyes, ears, nervous system, muscles, spleen, and kidneys. The c.594insC and c.594dupC variants are most common. CONCLUSION The identification of the two novel ABHD5 gene variants has enriched the mutation spectrum of CDS. c.594insC or c.594dupC are hotspot mutations of this disease, albeit with no definitive correlation between the genotype and phenotype.
Humans ; Female ; Ichthyosiform Erythroderma, Congenital/genetics* ; Lipid Metabolism, Inborn Errors/genetics* ; Phenotype ; 1-Acylglycerol-3-Phosphate O-Acyltransferase/genetics* ; Mutation ; Muscular Diseases/genetics* ; Exome Sequencing ; Child ; Male ; Child, Preschool