OBJECTIVE: To explore the genetic basis for a child affected with cerebral creatine deficiency syndrome 1 (CCDS1). METHODS: High-throughput sequencing was carried out to screen pathogenic variant associated with the clinical phenotype of the proband. The candidate variant was verified by Sanger sequencing. RESULTS: High-throughput sequencing revealed that the proband has carried heterozygous c.327delG variant of the SLC6A8 gene, which was verified by Sanger sequencing.Neither parent was found to carry the same variant. CONCLUSION The de novo heterozygous c.327delG variant of the SLC6A8 gene probably underlay the CCDS1 in this child.
Brain Diseases, Metabolic, Inborn/genetics* ; Creatine ; Genetic Testing ; Heterozygote ; Humans ; Mental Retardation, X-Linked ; Mutation

OBJECTIVE: To analyze the clinical features and genetic variants in four neonates with very long chain acyl-coenzyme A dehydrogenase (VLCAD) deficiency. METHODS: Neonates with a tetradecenoylcarnitine (C14:1) concentration at above 0.4 μmol/L in newborn screening were recalled for re-testing. Four neonates were diagnosed with VLCAD deficiency by MS-MS and genetic testing, and their clinical features and genotypes were analyzed. RESULTS: All cases had elevated blood C14:1, and the values of first recalls were all lower than the initial test. In 2 cases, the C14:1 had dropped to the normal range. 1 case has remained at above 1 μmol/L after the reduction, and the remainder one case was slightly decreased. In total eight variants of the ADACVL genes were detected among the four neonates, which included 5 missense variants and 3 novel variants (p.Met344Val, p.Ala416Val, c.1077+6T>A). No neonate showed salient clinical manifestations. CONCLUSION Above findings have enriched the spectrum of ADACVL gene mutations and provided a valuable reference for the screening and diagnosis of VLCAD deficiency.
Acyl-CoA Dehydrogenase/genetics* ; Acyl-CoA Dehydrogenase, Long-Chain ; Congenital Bone Marrow Failure Syndromes ; Genetic Testing ; Humans ; Infant, Newborn ; Lipid Metabolism, Inborn Errors ; Mitochondrial Diseases ; Muscular Diseases ; Tandem Mass Spectrometry

OBJECTIVE: To investigate the genetic etiology, clinical diagnosis and treatment of a child with pancytopenia, failure to thrive and pulmonary infection. METHODS: Peripheral blood samples of the child and her parents were collected. Genomic DNA was extracted. Genetic variants associated with hematological diseases were detected by high-throughput sequencing. RESULTS: Three variants of TCN2 gene were found, one of which located in exon 5 upstream(c.581-8A>T), the parents has carried this variant; one in exon 6 (c.924_927del), the variant was originated from the mother; one in exon 7 (c.973C>T), the variant has ocurred de novo. The variants pathogenic analysis combined with clinical manifestation, pancytopenia, the increase in methylmalonic acid level and increased homocysteine, the child was diagnosed with transcobalaminIIdeficiency. The patient presented with respiratory infection, which was confirmed to be pneumocystosis by lung radioscopy and pathogenic high-throughput sequencing of broncho-alveolar lavage fluid. The patient presented with acute respiratory distress syndrome during the treatment with intramuscular injection of vitamin B CONCLUSION We reported a case of Chinese child with TCNII deficiency due to novel gene variant, and analyzed the pathogenicity of the three variants. The treatment of TCNII deficiency with cobalamin should be individualized.
Amino Acid Metabolism, Inborn Errors ; Child ; Female ; Genetic Testing ; Humans ; Rare Diseases ; Transcobalamins/genetics* ; Vitamin B 12

OBJECTIVE: To study the application value of whole exome sequencing (WES) in critically ill neonates with inherited diseases. METHODS: A total of 66 critically ill neonates with suspected inherited diseases or unclear clinical diagnosis who were admitted to the neonatal intensive care unit were enrolled as subjects. The clinical data of the neonates were collected, and venous blood samples were collected from the neonates and their parents for WES. The clinical manifestations of the neonates were observed to search for related pathogenic gene mutations. RESULTS: Among the 66 critically ill neonates with suspected inherited diseases or unclear clinical diagnosis (34 boys and 32 girls), 14 (21%) were found to have gene mutations by WES. One neonate had no gene mutation detected by WES but was highly suspected of pigment incontinence based on clinical manifestations, and multiplex ligation-dependent probe amplification detected a heterozygous deletion mutation in exons 4-10 of the IKBKG gene. Among the 15 neonates with gene mutations, 10 (67%) had pathogenic gene mutation, 1 (7%) was suspected of pathogenic gene mutation, and 4 (27%) had gene mutations with unknown significance. Among the 15 neonates, 13 underwent chromosome examination, and only 1 neonate was found to have chromosome abnormality. CONCLUSIONS Chromosome examination cannot be used as a diagnostic method for inherited diseases, and WES detection technology is an important tool to find inherited diseases in critically ill neonates with suspected inherited diseases or unclear clinical diagnosis; however WES technology has some limitation and it is thus necessary to combine with other sequencing methods to achieve an early diagnosis.
Critical Illness ; Exons ; Female ; Genetic Diseases, Inborn/genetics* ; Heterozygote ; Humans ; I-kappa B Kinase/genetics* ; Infant, Newborn ; Male ; Mutation ; Whole Exome Sequencing

Follow-up is a crucial step for the screening of neonatal genetic and metabolic diseases, which can directly influence the detection, diagnosis, efficacy of treatment, as well as the quality of neonatal screening. In view of the lack of follow-up, full understanding, and inconsistent requirement between various agencies and personnel in China, there is an urgent need for standardization. The Committee for Proficiency Testing of the Neonatal Genetic Metabolic Disease Screening Center of the National Health Committee of China has organized the writing of expert consensus for follow-up of neonatal genetic and metabolic disease screening after thorough discussion, so as to guide the follow-up work and improve its quality.
China ; Consensus ; Follow-Up Studies ; Genetic Diseases, Inborn ; diagnosis ; Humans ; Infant, Newborn ; Metabolic Diseases ; diagnosis ; genetics ; Neonatal Screening

Consensus ; Genetic Diseases, Inborn ; diagnosis ; genetics ; Genome, Human ; genetics ; High-Throughput Nucleotide Sequencing ; Humans ; Practice Guidelines as Topic ; Sequence Analysis, DNA ; Whole Genome Sequencing

Hyperornithinemia-hyperammonemia-homocitrullinuria syndrome (HHH syndrome) is a neurometabolic disorder with highly variable clinical severity ranging from mild learning disability to severe encephalopathy. Diagnosis of HHH syndrome can easily be delayed or misdiagnosed due to insidious symptoms and incomplete biochemical findings, in that case, genetic testing should be considered to confirm the diagnosis. HHH syndrome is caused by biallelic mutations of SLC25A15, which is involved in the urea cycle and the ornithine transport into mitochondria. Here we report a boy with spastic paraplegia and asymptomatic younger sister who have compound heterozygous mutations of c.535C>T (p.R179*) and c.116C>A (p.T39K) in the SLC25A15 gene. We identified that p.T39K mutation is a novel pathogenic mutation causing HHH syndrome and that p.R179*, which is prevalent in Japanese and Middle Eastern heritage, is also found in the Korean population.
Asian Continental Ancestry Group ; Brain Diseases ; Diagnosis ; Genetic Testing ; Genetics ; Humans ; Learning Disorders ; Male ; Mitochondria ; Ornithine ; Paraplegia ; Siblings ; Urea ; Urea Cycle Disorders, Inborn

OBJECTIVETo detect potential mutations of MAT1A gene in a child suspected with simple hypermethioninemia by MS/MS neonatal screening.

METHODSClinical data of the child was collected. Genomic DNA was extracted by a standard method and subjected to targeted sequencing using an Ion AmpliseqInherited Disease Panel. Detected mutations were verified by Sanger sequencing.

RESULTSThe child showed no clinical features except evaluated methionine. A novel compound mutation of the MAT1A gene, i.e., c.345delA and c.529C>T, was identified in the child. His father and mother were found to be heterozygous for the c.345delA mutation and c.529C>T mutation, respectively.

CONCLUSIONThe compound mutation c.345delA and c.529C>T of the MAT1A gene probably underlie the disease in the child. The semi-conductor sequencing has provided an important means for the diagnosis of hereditary diseases.

Amino Acid Metabolism, Inborn Errors ; genetics ; pathology ; Base Sequence ; DNA Mutational Analysis ; methods ; Family Health ; Fathers ; Female ; Genetic Predisposition to Disease ; genetics ; Glycine N-Methyltransferase ; deficiency ; genetics ; Heterozygote ; Humans ; Infant, Newborn ; Infant, Newborn, Diseases ; genetics ; pathology ; Male ; Methionine Adenosyltransferase ; genetics ; Mothers ; Mutation

More than 7000 single gene diseases have been identified and most of them lack effective treatment. As an early form of prenatal diagnosis, preimplantation genetic diagnosis (PGD) is a combination of in vitro fertilization and genetic diagnosis. PGD has been applied in clinics for more than 20 years to avoid the transmission of genetic defects through analysis of embryos at early stages of development. In this paper, a review for the recent advances in PGD for single gene diseases is provided.
Animals ; Female ; Fertilization in Vitro ; Genetic Diseases, Inborn ; diagnosis ; embryology ; genetics ; Humans ; Pregnancy ; Preimplantation Diagnosis ; methods ; trends ; Prenatal Diagnosis ; methods ; trends

BACKGROUND: A newborn screening (NBS) program has been utilized to detect asymptomatic newborns with inherited metabolic diseases (IMDs). There have been some bottlenecks such as false-positives and imprecision in the current NBS tests. To overcome these issues, we developed a multigene panel for IMD testing and investigated the utility of our integrated screening model in a routine NBS environment. We also evaluated the genetic epidemiologic characteristics of IMDs in a Korean population. METHODS: In total, 269 dried blood spots with positive results from current NBS tests were collected from 120,700 consecutive newborns. We screened 97 genes related to NBS in Korea and detected IMDs, using an integrated screening model based on biochemical tests and next-generation sequencing (NGS) called NewbornSeq. Haplotype analysis was conducted to detect founder effects. RESULTS: The overall positive rate of IMDs was 20%. We identified 10 additional newborns with preventable IMDs that would not have been detected prior to the implementation of our NGS-based platform NewbornSeq. The incidence of IMDs was approximately 1 in 2,235 births. Haplotype analysis demonstrated founder effects in p.Y138X in DUOXA2, p.R885Q in DUOX2, p.Y439C in PCCB, p.R285Pfs*2 in SLC25A13, and p.R224Q in GALT. CONCLUSIONS: Through a population-based study in the NBS environment, we highlight the screening and epidemiological implications of NGS. The integrated screening model will effectively contribute to public health by enabling faster and more accurate IMD detection through NBS. This study suggested founder mutations as an explanation for recurrent IMD-causing mutations in the Korean population.
Computational Biology ; DNA/chemistry/isolation & purification/metabolism ; Dried Blood Spot Testing ; Galactokinase ; Genomics ; Haplotypes ; High-Throughput Nucleotide Sequencing ; Humans ; Incidence ; Infant, Newborn ; Membrane Proteins/genetics ; Metabolic Diseases/*diagnosis/epidemiology/genetics ; Metabolism, Inborn Errors/diagnosis/epidemiology/genetics ; Mitochondrial Membrane Transport Proteins/genetics ; Neonatal Screening ; Polymorphism, Genetic ; Republic of Korea/epidemiology ; Sequence Analysis, DNA