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

Multiple carboxylase deficiency (MCD) includes autosomal recessive holocarboxylase synthetase (HLCS) deficiency and biotinidase (BTD) deficiency, which are caused by and gene mutations respectively. Neonatal screening for HLCS deficiency is based on 3-hydroxyisovaleryl carnitine in dry blood filter paper, and BTD deficiency is based on BTD activity determination. HLCS deficiency and BTD deficiency are characterized by neurocutaneous syndrome and organic aciduria, however, they are different in onset age, neurological symptoms and metabolic decompensation, which needed to be differentiated from acquired biotin deficiency or other genetic metabolic diseases. The diagnosis of the disease requires a combination of biochemical characteristics of hematuria, enzyme activity determination and genetic test. Routine biotin doses are effective for most MCD patients. This consensus is intended to benefit early screening and diagnosis of MCD.
Biotin/therapeutic use* ; Biotinidase Deficiency/therapy* ; Carbon-Nitrogen Ligases/metabolism* ; Consensus ; Holocarboxylase Synthetase Deficiency/genetics* ; Humans ; Infant, Newborn ; Multiple Carboxylase Deficiency/drug therapy* ; Neonatal Screening

OBJECTIVE: To explore the genetic basis for a child with clinically suspected 3-methylcrotonyl-coenzyme A carboxylase deficiency (MCCD). METHODS: Genomic DNA was extracted from peripheral blood samples of the proband and her parents. Whole exome sequencing was used to screen pathogenic variant in the proband. Suspected variant was verified by Sanger sequencing. Impact of the variant on the structure and function of protein product was analyzed by using bioinformatic software. RESULTS: Sanger sequencing showed that the proband has carried homozygous missense c.1342G>A (p.Gly448Ala) variant of the MCCC2 gene, for which her mother was a heterozygous carrier. The same variant was not detected in her father. The variant was predicted to be pathogenic by PolyPhen-2 and Mutation Taster software, and the site was highly conserved among various species. Based on the American College of Medical Genetics and Genomics standards and guidelines, the c.1342G>A (p.Gly448Ala) variant of MCCC2 gene was predicted to be likely pathogenic(PM2+PP2-PP5). CONCLUSION The homozygous missense variant of the MCCC2 gene c.1342G>A (p.Gly448Ala) probably underlay the molecular pathogenesis of the proband. Genetic testing has confirmed the clinical diagnosis.
Carbon-Carbon Ligases/genetics* ; Child ; Female ; Humans ; Male ; Mutation, Missense/genetics* ; Pedigree ; Urea Cycle Disorders, Inborn/genetics*

OBJECTIVE: To explore the genetic basis for a patient featuring multiple carboxylase deficiency (MCD). METHODS: PCR and Sanger sequencing were used to detect variant in the coding region of BT and HLCS genes in the patient. Suspected variants were verified in her parents and 80 unrelated healthy controls by a PCR-restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: The patient was found to carry compound heterozygous variants of the HLCS gene, namely c.286delG (p.Val96Leufs*162) and c.1648G>A (p.Val550Met). The c.286delG (p.Val96Leufs*162) was verified to be novel variant based on the result of PCR-RFLP analysis. No variant was found in the coding regions of BT gene in the patient. CONCLUSION The compound c.286delG (p.Val96Leufs*162) and c.1648G>A (p.Val550Met) variants probably underlie the MCD disorder in this patient. Above results have enriched the variant spectrum of MCA.
Carbon-Nitrogen Ligases ; genetics ; Exons ; Female ; Humans ; Multiple Carboxylase Deficiency ; genetics ; Mutation ; Open Reading Frames ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Sequence Analysis, DNA

OBJECTIVE: To investigate the genetic characterization of 3-hydroxyisovalerylcarnitine (C5-OH) metabolic abnormality in neonates. METHODS: Fifty two newborns with increased C5-OH, C5-OH/C3 and C5-OH/C8 detected by tandem mass spectrometry during neonatal screening were enrolled in the study. Genomic DNA was extracted from the whole blood samples of 52 cases and their parents. Seventy-nine genes associated with genetic and metabolic diseases including , were targeted by liquid capture technique. Variation information of these genes was examined by high-throughput sequencing and bioinformatic analysis, and then was classified based on the American College of Medical Genetics and Genomics (ACMG) standards and guidelines. The genetic types were classified as wild-type, -maternal-mutation, -paternal-mutation and -mutation. Wilcoxon rank-sum test was performed for the increased multiples of C5-OH calculated in neonatal screening. RESULTS: Twenty one variants (14 novel) were identified in 37 cases, 6 variants (5 novel) in 4 cases. The increased multiple of C5-OH calculated in -maternal-mutation and -mutation groups were significantly higher than that in wild-type group (all <0.05), while there was no significant difference between MCCC1-paternal-mutation group and wild-type group (>0.05). CONCLUSIONS Mutations on and genes are the major genetic causes for the increased C5-OH in neonates, and maternal single heterozygous mutation can contribute to the moderately to severely increased C5-OH.
Carbon-Carbon Ligases ; genetics ; Carnitine ; analogs & derivatives ; metabolism ; Female ; Genetic Testing ; Genetic Variation ; Humans ; Infant, Newborn ; Male ; Mutation ; Neonatal Screening ; Urea Cycle Disorders, Inborn ; genetics

Recombinant strains expressing enzymes for ATP regeneration and L-theanine production were constructed and used for the synthesis of L-theanine. The ppk gene encoding polyphosphate kinase (PPK) from Rhodobacter sphaeroides and gmas gene encoding γ-glutamylmethylamide synthetase (GMAS) from Methylovorus mays were synthesized, and two recombinant plasmids, pETDuet-ppk+gmas and pET21a-ppk+gmas were constructed for co-expression of PPK and GMAS in Escherichia coli BL21(DE3). SDS-PAGE analysis showed that PPK and GMAS were overexpressed in soluble form in both recombinant strains. GMAS-PPK obtained from the recombinant strain containing pET21a-ppk+gmas was more efficient to synthesize L-theanine. After 24 h at 37 ℃ and pH at 7.0, 86.0% yield of L-theanine was achieved with catalytic amount of ATP. This study extends the application of enzymatic ATP regeneration system. In addition, it provides an efficient method for the biosynthesis of L-theanine.
Carbon-Nitrogen Ligases ; genetics ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli ; genetics ; Glutamates ; biosynthesis ; Ligases ; Phosphotransferases (Phosphate Group Acceptor) ; genetics

OBJECTIVETo explore the molecular mechanism for a boy suspected with 3-methylcrotonyl-CoA carboxylase deficiency by neonatal screening.

METHODSPCR and Sanger sequencing were used to identify potential mutations of MCCC1 and MCCC2 genes. SIFT and Polyphen-2 software was used to predict the effect of variant on the protein function and conservation of the variant across various species. Human Splicing Finder and Swiss-PdbViewer4.1.0 were applied to analyze the possible mechanism of the variant.

RESULTSFor the proband, a compound heterozygous mutation was discovered in the MCCC1 gene, namely c.539G>T (p.G180V) and c.704_711del (p.A235Vfs*4), which were inherited from his father and mother, respectively. The two mutations have disrupted the protein conformation, which in turn may impact the function of MCC protein.

CONCLUSIONThe compound heterozygous mutations of the MCCC1 gene may contribute to the 3-methylcrotonyl-CoA carboxylase deficiency manifested by the patient.

Amino Acid Sequence ; Base Sequence ; Carbon-Carbon Ligases ; chemistry ; deficiency ; genetics ; DNA Mutational Analysis ; Heterozygote ; Humans ; Infant, Newborn ; Male ; Models, Molecular ; Mutation ; Neonatal Screening ; methods ; Protein Conformation ; Sequence Homology, Amino Acid ; Urea Cycle Disorders, Inborn ; diagnosis ; genetics

BACKGROUND: Recently, the iNtRON VRE vanA/vanB real-time PCR (iNtRON; iNtRON Biotechnology, Korea) assay, a multiplex real-time PCR method, was introduced. In this prospective study, we compared the iNtRON assay with the Seeplex VRE ACE detection kit (Seeplex; Seegene, Korea), a conventional multiplex PCR assay. METHODS: A chromogenic agar-based culture, in which pre-selected vancomycin-resistant enterococci (VRE) was grown and subsequently plated on blood agar with vancomycin disks, was regarded as the reference method. A total of 304 consecutive rectal swab specimens were tested for VRE by culture and by iNtRON and Seeplex PCR assays. For the PCR assays, specimens were enriched for 16-24 hr before PCR. RESULTS: VRE were isolated from 44 (14.5%) specimens by chromogenic agar-based culture. The clinical sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the iNtRON assay were 100% (95% confidence interval: 89.8%-100%), 99.2% (96.9%-99.9%), 95.6% (83.6%-99.2%), and 100% (98.2%-100%), respectively, while those of the Seeplex assay were 97.7% (86.2%-99.9%), 99.6% (97.5%-99.9%), 97.7% (86.2%-99.9%), and 99.6% (97.5%-99.9%), respectively. The iNtRON assay had a detection limit of 3,159 copies/microL and 13,702 copies/microL for the vanA and vanB genes, respectively. No cross-reactivity was observed in 11 non-VRE bacterial culture isolates. CONCLUSIONS: The overall performance of the iNtRON assay was comparable to that of a chromogenic agar-based culture method for prompt identification of VRE-colonized patients in hospitals. This assay could be an alternative or supportive method for the effective control of nosocomial VRE infection.
Bacterial Proteins/*genetics ; Bacterial Typing Techniques/*methods/standards ; Carbon-Oxygen Ligases/*genetics ; DNA, Bacterial/*metabolism ; Gram-Positive Bacterial Infections/microbiology ; Humans ; Reagent Kits, Diagnostic ; *Real-Time Polymerase Chain Reaction ; Vancomycin Resistance/genetics ; Vancomycin-Resistant Enterococci/*genetics/isolation & purification

BACKGROUND: The aim of this study was to evaluate a newly developed PCR-based reverse blot hybridization assay (PCR-REBA), REBA Sepsis-ID (M&D, Wonju, Korea), to rapidly detect the presence of bacteremia and antimicrobial resistance gene in blood culture samples. METHODS: One thousand four hundred consecutive blood culture samples from patients with a delta neutrophil index greater than 2.7% were selected from March to July in 2013. Three hundred positive and 1,100 negative for bacterial growth in blood culture bottles samples were tested by conventional and real-time PCR-REBA, respectively. RESULTS: The overall agreement between the conventional identification test and the REBA Sepsis-ID test was 95.3% (286/300). Agreement for gram-positive bacteria, gram-negative bacteria, fungi, and polymicrobials was 94.5% (190/201), 97.3% (71/73), 100% (14/14), and 91.7% (11/12), respectively. The detection rate of the mecA gene from methicillin-resistant Staphylococcus isolates was 97.8% (90/92). The vanA gene was detected in one blood culture sample from which vancomycin-resistant Enterococcus was isolated. When the cycle threshold for real-time PCR was defined as 30.0, 2.4% (26/1,100) of negative blood culture samples tested positive by real-time PCR. CONCLUSIONS: The REBA Sepsis-ID test is capable of simultaneously and quickly detecting both causative agents and antimicrobial resistance genes, such as mecA and van, in blood culture positive samples.
Bacteremia/microbiology ; Bacterial Proteins/*genetics ; Bacteriological Techniques/*methods ; Carbon-Oxygen Ligases/*genetics ; Drug Resistance, Bacterial/genetics ; Enterococcus/*genetics/isolation & purification ; Humans ; Methicillin-Resistant Staphylococcus aureus/*genetics/isolation & purification ; *Nucleic Acid Hybridization ; RNA, Ribosomal, 16S/analysis ; Reagent Kits, Diagnostic ; *Real-Time Polymerase Chain Reaction

OBJECTIVETo study the feasibility of using methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) for the detection of DNA methylation in placenta tissue.

METHODSFor blood cells from 13 non-pregnant women and 9 euploid placenta, the ratios of DNA methylation were evaluated for 4 genes including CGI149, CGI113, HLCS and ACTB with MS-MLPA and bisulfite sequencing, respectively.

RESULTSThe methylation ratio of the ACTB gene was 0-0.1 for the blood cells when the digestion control was completely digested. The cutoff value for the methylation ratio of MS-MLPA has been determined as 0.1. For the 9 placenta samples, results of MS-MLPA and bisulfite sequencing were concordant for all of the four genes.

CONCLUSIONMS-MLPA is an effective alternative to bisulfite sequencing for the assessment of methylation ratios in placental tissues.

Actins ; genetics ; Adult ; Carbon-Nitrogen Ligases ; genetics ; CpG Islands ; genetics ; DNA Methylation ; Endosomal Sorting Complexes Required for Transport ; genetics ; Feasibility Studies ; Female ; Humans ; Multiplex Polymerase Chain Reaction ; methods ; Placenta ; metabolism ; Pregnancy ; Reproducibility of Results ; Ribosomal Proteins ; genetics ; Young Adult