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

Crigler-Najjar syndrome (CNS) and Gilbert syndrome (GS; OMIM: 143500) are rare autosomal recessive diseases that cause unconjugated hyperbilirubinemia due to decreased UGT1A1 enzyme activity. Crigler-Najjar syndrome type 2 (CNS2; OMIM: 606785) increases the risk of gallbladder stone formation and cholecystitis, while GS seldom causes health issues. We found a 28-year-old male patient with recurring right upper abdomen pain who experienced persistent jaundice from birth. CNS2 with gallbladder stones and cholecystitis was diagnosed after genetic testing revealed rare double homozygous mutations A(TA)₇TAA (rs3064744) and P229Q (rs35350960) in the UGT1A1 gene. After pedigree investigation, we found that the patient's parents with modestly increased bilirubin had compound heterozygous mutations A(TA)₇TAA and P229Q, which were GS. Bioinformatics analysis showed that A(TA)₇TAA is in the TATA-box region of the gene UGT1A1 promoter, affecting gene transcriptional initiation, whereas P229Q modifies protein three-dimensional structure and may be harmful. In this pedigree, double homozygous mutations have a more severe phenotype than compound heterozygous mutations. Inherited causes of hyperbilirubinemia should be suspected after ruling out biliary obstruction, and early bilirubin reduction (< 103 µmol/L (6 mg/dL)) may reduce the risk of complications like cholecystitis in CNS2 patients, though further studies with longer follow-up are needed to confirm this observation.
Humans ; Male ; Glucuronosyltransferase/genetics* ; Adult ; Crigler-Najjar Syndrome/complications* ; Cholecystitis/etiology* ; Homozygote ; Mutation ; Pedigree

OBJECTIVES: To investigate the molecular epidemiology of children with phenylketonuria (PKU) in Gansu, China, providing foundational data for intervention strategies. METHODS: A retrospective analysis was conducted on 1 159 PKU families who attended Gansu Provincial Maternity and Child Care Hospital from January 2012 to December 2024. Sanger sequencing, multiplex ligation-dependent probe amplification, whole exome sequencing, and deep intronic variant analysis were used to analyze the <i>PAHi> gene. RESULTS: For the 1 159 children with PKU, 2 295 variants were identified in 2 318 alleles, resulting in a detection rate of 99.01%. The detection rates were 100% (914/914) in 457 classic PKU families, 99.45% (907/912) in 456 mild PKU families, and 96.34% (474/492) in 246 mild hyperphenylalaninemia families. The 2 295 variants detected comprised 208 distinct mutation types, among which c.728G>A (14.95%, 343/2 295) had the highest frequency, followed by c.611A>G (4.88%, 112/2 295) and c.721C>T (4.79%, 110/2 295). The cumulative frequency of the top 23 hotspot variants reached 70.28% (1 613/2 295), and most variant alleles were detected in exon 7 (29.19%, 670/2 295). CONCLUSIONS Deep intronic variant analysis of the <i>PAHi> gene can improve the genetic diagnostic rate of PKU. The development of targeted detection kits for <i>PAHi> hotspot variants may enable precision screening programs and enhance preventive strategies for PKU.
Humans ; Phenylketonurias/epidemiology* ; Female ; Male ; Retrospective Studies ; Phenylalanine Hydroxylase/genetics* ; Mutation ; Child, Preschool ; China/epidemiology* ; Child ; Infant

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 <i>PCCAi> 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 <i>MMUTi> 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 <i>PCCAi> 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 investigate the growth parameters of children with phenylketonuria and assess the impact of a phenylalanine-restricted diet on their physical development. METHODS: The study involved 39 children diagnosed with phenylketonuria through newborn screening at the Central Child Teaching Hospital, Baghdad, Iraq. Data were collected during scheduled monthly check-ups, including phenylalanine levels, diet compliance, and anthropometric measurements. The children were divided into two groups based on their phenylalanine levels during the 3-year follow-up period: well-controlled group (average phenylalanine level of less than 360 μmol/L, with no single reading exceeding 600 μmol/L; <i>ni>=14) and poorly-controlled group (one or more phenylalanine readings above 600 μmol/L during the follow-up period; <i>ni>=25). RESULTS: The mean height readings for all time points (at birth and 3, 6, 9, 12, 15, 18, 21, 24 and 36 months of age) were higher in the well-controlled group than the poorly-controlled group, however, only at 3 months of age the difference was statistically significant. Height Z-scores revealed a clearer pattern: although the poorly-controlled group had higher height Z-scores at birth (<i>Pi>=0.001), the well-controlled group showed significantly higher height Z-scores at 3, 6, 12, 15, 18, 24, and 36 months (<i>Pi><0.05). The well-controlled group exhibited significantly higher mean weight measurements compared to the poorly-controlled group at 3, 6, 9, 15, 18 months and 21 months (<i>Pi><0.05). From 6 to 36 months, the well-controlled group consistently had significantly higher weight Z-scores than the poorly-controlled group (<i>Pi><0.05). The well-controlled group showed more favorable height and weight Z-score distributions at 36 months of age compared to the poorly-controlled group, but the differences were not statistically significant (<i>Pi>>0.05). Both groups had height and weight Z-scores within the normal range at 36 months of age. CONCLUSIONS The children with phenylketonuria who receive good dietary control show better improvements in growth parameters compared to those with poor dietary control, however, both groups maintain height and weight Z-scores within the normal range, indicating generally adequate physical development across the cohort.
Humans ; Phenylketonurias/diet therapy* ; Male ; Female ; Child, Preschool ; Infant ; Body Height ; Infant, Newborn ; Child Development ; Phenylalanine/blood*

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 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 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 spectrum of genetic variants and phenotypes of Phenylalanine hydroxylase deficiency (PAHD) in Lianyungang area and the correlation between genotype and phenotypes among the patients. METHODS: Eighty children with Hyperphenylalaninemia (HPA) diagnosed at the Lianyungang Branch of Jiangsu Provincial Newborn Screening Center between January 2015 and December 2022 were enrolled. Peripheral blood samples were collected for genetic analysis using next generation sequencing (NGS), Sanger sequencing, and multiplex ligation-dependent probe amplification (MLPA) to identify the variants of PAH gene. Clinical and phenotypic data were concurrently analyzed to investigate the correlation between the types of PAH gene variant and phenotypes. This study was approved by the Medical Ethics Committee of Lianyungang Maternal and Child Health Care Hospital (Ethics No.: XM2022041). RESULTS: PAH gene variants were identified in 93.75% (75/80) of the children, classified as PAHD cases, while 6.25% (5/80) harbored PTS gene variants. Of the 150 PAH alleles from 75 PAHD children, a total of 152 variants (55 distinct types) were detected, with a detection rate of 100%. 80.26% (122/152) of the variants were located in exons, with the main types being missense variants (67.11%, 102/152). 53.29% (81/152) of coding sequence variants have occurred in the PAH gene's catalytic center region, while 19.74% (30/152) of the variants involved non-coding sequences. The phenotypes of the 75 PAHD children were evenly distributed. The re-screened Phe concentrations and Phe/Tyr ratios of classic-phenylketonuria (CPKU) and mild-phenylketonuria (MPKU) patients were markedly higher than initial screening values (P < 0.001, P < 0.001; P = 0.004, P = 0.016). The genotypes of the PAHD patients mostly occurred as compound heterozygotes, and different mutation positions and variant types have significantly affected the phenotypes (P = 0.042, P = 0.045). APV/GPV genotype-phenotype analysis of 61 patients showed high consistency between predicted and actual phenotypes (κ = 0.755, P < 0.001). CONCLUSION PAH gene variants were detected in most HPA children from Lianyungang area. The location and type of PAH gene variants has correlated with the severity of the phenotype, and the non-coding sequence variants and non-missense variants may aggravate the phenotype, and the APV/GPV model has predicted the phenotype with high consistency with the actual phenotype.
Humans ; Phenylalanine Hydroxylase/genetics* ; Female ; Phenylketonurias/enzymology* ; Male ; Phenotype ; Genotype ; Child ; Infant ; Infant, Newborn ; Child, Preschool ; China ; Mutation ; Alleles

OBJECTIVE: To investigate the clinical manifestations and genetic characteristics of a child with glycogen storage disease type III (GSD-III) complicated with Guillain-Barré syndrome (GBS) caused by AGL gene variants, and to analyze the pathogenesis, potential correlation, treatment and prognosis of the two diseases. METHODS: A child with GSD-III who visited the General Hospital of Ningxia Medical University due to "limb weakness for more than ten days" in July 2024 was selected as the study subject. Clinical data of the child were collected. Peripheral blood samples of the child and his parents were collected for whole exome sequencing and Sanger sequencing. Candidate variants were verified, and pathogenicity analysis was conducted for the variant sites. This study was approved by the Medical Ethics Committee of General Hospital of Ningxia Medical University (Ethics No.: KYLL-2025-1984). RESULTS: The child has presented with inability to stand or walk independently, difficulty in grasping, accompanied by numbness and pain at the distal end, choking when drinking water, occasional non-projectile vomiting, and enlargement of liver and spleen. Laboratory tests showed abnormal liver function and a significant increase in creatine kinase. Color Doppler ultrasound of the heart showed an enlarged left atrium and mild regurgitation of mitral and tricuspid valves. Genetic testing confirmed that he has harbored compound heterozygous variants of the AGL gene, namely c.1611G>A (p.E537E) and c.579del (p.W194Gfs*7), which were inherited from his father and mother, respectively. According to the guidelines from the American Collage for Medical Genetics and Genomics (ACMG), the two variants were respectively predicted as variant of unknown significance (PM2_Supporting+PM3+PP3_Supporting) and likely pathogenic (PVS1+PM2_Supporting). Electrophysiological examination confirmed that the child had severe damage to the motor and sensory nerves accompanied by axonal injury, which was consistent with the axonal variant type of GBS -acute motor and sensory axonal neuropathy. After a clear diagnosis, the child was treated with intravenous human immunoglobulin. His condition deteriorated progressively, presenting with breathing difficulties, liver failure, and gastrointestinal bleeding, and eventually deceased due to multiple organ failures. CONCLUSION The etiology of GSD-III and GBS involves multiple aspects such as genetics, metabolism and immunity. In clinical practice, it should be noted that similar clinical manifestations may occur in both conditions. Close attention should be paid to the patients' blood glucose, blood gas, coagulation function and liver function, etc. Clinical intervention should be carried out as early as possible to improve the prognosis.
Humans ; Male ; Guillain-Barre Syndrome/complications* ; Glycogen Storage Disease Type III/complications* ; Mutation ; Child