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 for a neonate affected with Glutaric aciduria type I (GA-I). METHODS: Targeted capture and high-throughput sequencing was carried out for the proband and her parents. Candidate variants were verified by Sanger sequencing. RESULTS: The proband was found to harbor compound heterozygous variants of the GCDH gene, namely c.523G>A and c.1190T>C, which was derived from her father and mother, respectively. CONCLUSION The compound heterozygous variants of the GCDH gene probably underlay the GA-I in the patient.
Amino Acid Metabolism, Inborn Errors/genetics* ; Brain Diseases, Metabolic/genetics* ; Child ; Female ; Glutaryl-CoA Dehydrogenase/genetics* ; High-Throughput Nucleotide Sequencing ; Humans ; Infant, Newborn ; Mutation

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 review the clinical features of a male twin affected with glutaric academia type I (GA-I) and analyze the variations of glutaryl-CoA dehydrogenase (GCDH) gene. METHODS: Clinical data of the pair of twins and their parents were collected. Genomic DNA was extracted from peripheral blood samples, and variants of GCDH genes were detected by capture sequencing using a customized panel. Variants of the twins and their parents were verified by Sanger sequencing. RESULTS: The level of glutaric acyl carnitine (C5DC + C6OH) was 3.26 μmol/L in the male twin. The relative level of glutaric acid in urine was 547.51 by gas chromatography mass spectrometry analysis. Cerebral ultrasonography showed that the patient had subependymal hemorrhage, but no serious clinical manifestation was noted. After treating with special formula milk powder and L-carnitine, the boy showed good growth and development. Two heterozygous variants of the GCDH gene were detected in the patient, among which c.416C>G was suspected to be pathogenic, while c.109_110delCA was unreported. The variants were respectively inherited from his parents. The twin girl only carried the c.416C>G variant. CONCLUSION GA-I can be diagnosed by mass spectrometry, urine gas chromatographic mass spectrometry, imaging as well as genetic diagnosis. Early diagnosis and intervention is important.
Amino Acid Metabolism, Inborn Errors ; genetics ; Brain Diseases, Metabolic ; genetics ; Female ; Glutaryl-CoA Dehydrogenase ; deficiency ; genetics ; Humans ; Male ; Mutation ; Phenotype

OBJECTIVE: To screen for potential variants of GCDH gene in 3 patients clinically diagnosed as glutaric aciduria type Ⅰ. METHODS: GCDH gene variants was detected by Sanger sequencing among the three children and their family members. RESULTS: Sanger sequencing showed that patient 1 carried compound heterozygosity variants of c.532G>A (p.Gly178Arg) and c.655G>A (p.Ala219Thr) of the GCDH gene, while his father and mother respectively carried heterozygous c.532G>A(p.Gly178Arg) and c.655G>A (p.Ala219Thr) variants. Patient 2 carried c.532G>A (p.Gly178Arg) and a novel c.1060G>T (p.Gly354Cys) compound heterozygous variant, while his father and mother respectively carried heterozygous c.532G>A (p.Gly178Arg) and c.1060G>T (p.Gly354Cys) variant. Patient 3 carried homozygous c.532G>A (p.Gly178Arg) variant of the GCDH gene, for which both of his parents were heterozygous carriers. CONCLUSION The GCDH gene variant probably underlie the glutaric aciduria type Ⅰ among the 3 patients. Identifcation of the novel variant has enriched the spectrum of GCDH gene variants.
Amino Acid Metabolism, Inborn Errors ; genetics ; Brain Diseases, Metabolic ; genetics ; Female ; Glutaryl-CoA Dehydrogenase ; deficiency ; genetics ; Heterozygote ; Humans ; Male

OBJECTIVE: To detect potential variation in glutaryl-CoA dehydrogenase (GCDH) gene among three Chinese families affected with glutaric acidemia type Ⅰ(GA-1) and correlate the genotypes with phenotypes. METHODS: Genomic DNA was extracted from peripheral blood samples derived from three patients with GA-1 and their family members. The coding regions of the GCDH gene were amplified with PCR and subjected to Sanger sequencing. RESULTS: The clinical manifestation of the patients varied from macrocephaly to severe encephalopathy, with notable phenotypic difference between siblings carrying the same variation. In pedigrees 1 and 2, the probands have carried compound heterozygous variations c.1133C>T(p.Ala378Val) and c.1244-2A>C, which were derived their fathers and mothers, respectively. In pedigree 3, the proband has carried compound heterozygous variation c.339delT (p.Tyr113) and c.406G>T (p.Gly136Cys). Among these, variations c.339delT and c.1133C>T were verified as novel by retrieval of dsSNP, HGMD and 1000 genome database. Bioinformatic analysis suggested that above variations can affect protein function and are probably pathogenic. CONCLUSION Above discovery has expanded the mutation spectrum of the GCDH gene. No correlation was found between the clinical phenotype and genotype of GA-1 patients.
Amino Acid Metabolism, Inborn Errors ; diagnosis ; genetics ; Brain Diseases, Metabolic ; diagnosis ; genetics ; China ; DNA Mutational Analysis ; Glutaryl-CoA Dehydrogenase ; deficiency ; genetics ; Humans ; Mutation

OBJECTIVETo investigate the effect of glutaryl-CoA dehydrogenase (GCDH) gene silencing and accumulation of lysine metabolites on the viability of hepatocytes.

METHODSBRL cells were divided into normal control group, negative control group, and GCDH silencing group. The shRNA lentiviral vector for silencing GCDH gene was constructed, and the BRL hepatocytes in the GCDH silencing group and the negative control group were infected with this lentivirus and negative control virus respectively, and then cultured in a medium containing 5 mmol/L lysine. Immunofluorescence assay was used to measure the infection efficiency of lentivirus. Western blot was used to measure the expression of GCDH protein. MTT assay was used to evaluate cell viability. Hoechest33342 staining was used to measure cell apoptosis. Western blot was used to measure the expression of Caspase-3, an index of cell apoptosis.

RESULTSThe lentivirus constructed effectively silenced the GCDH gene in hepatocytes (P<0.01). MTT assay and Hoechest 33342 staining showed no significant differences in cell viability and apoptosis between groups (P>0.05). There was also no significant difference in the expression of Caspase-3 protein between groups (P>0.05).

CONCLUSIONSGCDH gene silencing and accumulation of lysine metabolites may not cause marked hepatocyte injury.

Amino Acid Metabolism, Inborn Errors ; pathology ; therapy ; Animals ; Apoptosis ; Brain Diseases, Metabolic ; pathology ; therapy ; Caspase 3 ; metabolism ; Cell Survival ; Cells, Cultured ; Fluorescent Antibody Technique ; Gene Silencing ; Glutaryl-CoA Dehydrogenase ; deficiency ; genetics ; Hepatocytes ; pathology ; Lysine ; metabolism ; Rats

Glutaric aciduria type 1 is a rare autosomal recessive disorder. GCDH gene mutations cause glutaryl-CoA dehydrogenase deficiency and accumulation of glutaric acid and 3-hydroxyglutaric acid, resulting in damage of striatum and other brain nucleus and neurodegeneration. Patients with glutaric aciduria type 1 present with complex heterogeneous phenotypes and genotypes. The symptoms are extremely variable. The ages of the clinical onset of the patients range from the fetus period to adulthood. The patients with mild glutaric aciduria type 1 are almost asymptomatic before onset, however, severe glutaric aciduria type 1 may cause death or disability due to acute encephalopathy. Acute metabolic crisis in patients with underlying glutaric aciduria type 1 is often triggered by febrile illnesses, trauma, hunger, high-protein foods and vaccination during a vulnerable period of brain development in infancy or early childhood. The early-onset patients usually have a poor prognosis. Urinary organic acids analysis, blood acylcarnitines analysis and GCDH study are important for the diagnosis of this disorder. Neonatal screening is essential for the early diagnosis and the improvement of prognosis.
Amino Acid Metabolism, Inborn Errors ; diagnosis ; genetics ; therapy ; Brain Diseases, Metabolic ; diagnosis ; genetics ; therapy ; Genotype ; Glutaryl-CoA Dehydrogenase ; deficiency ; genetics ; Humans ; Infant, Newborn ; Neonatal Screening ; Phenotype ; Prenatal Diagnosis ; Prognosis

A one-year-old girl visited the hospital due to limb torsion and developmental regression for one month after hand, foot and mouth disease. At the age of 11 months, she visited a local hospital due to fever for 5 days and skin rash with frequent convulsions for 2 days and was diagnosed with severe hand, foot and mouth disease, viral encephalitis, and status epilepticus. Brain MRI revealed symmetric abnormal signals in the bilateral basal ganglia, bilateral thalamus, cerebral peduncle, bilateral cortex, and hippocampus. She was given immunoglobulin, antiviral drugs, and anticonvulsant drugs for 2 weeks, and the effect was poor. Blood and urine screening for inherited metabolic diseases were performed to clarify the etiology. The analysis of urine organic acids showed significant increases in glutaric acid and 3-hydroxyglutaric acid, which suggested glutaric aciduria type 1, but her blood glutarylcarnitine was normal, and free carnitine significantly decreased. After the treatment with low-lysine diets, L-carnitine, and baclofen for 1 month, the patient showed a significant improvement in symptoms. Hand, foot and mouth disease is a common viral infectious disease in children, and children with underlying diseases such as inherited metabolic diseases and immunodeficiency may experience serious complications. For children with hand, foot and mouth disease and unexplained encephalopathy, inherited metabolic diseases should be considered.
Amino Acid Metabolism, Inborn Errors ; etiology ; Brain Diseases, Metabolic ; etiology ; Developmental Disabilities ; etiology ; Female ; Glutaryl-CoA Dehydrogenase ; deficiency ; Hand, Foot and Mouth Disease ; complications ; Humans ; Infant ; Torsion Abnormality ; etiology

OBJECTIVETo explore pathogenic mutation in a family affected with 2-hydroxyglutaric aciduria.

METHODSExons of 3 candidate genes, including L2HGDH, D2HGDH and SLC25A1, were amplified with polymerase chain reaction and subjected to direct sequencing.

RESULTSDNA sequencing has found that the proband and his affected younger brother have both carried a heterozygous mutation c.845G>A (p.R282Q) in the exon 7 of the L2HGDH gene. The same mutation was not detected in the his sister who was healthy. Pedigree analysis has confirmed that the above mutation was inherited from the mother. No mutation was detected in exons and flanking sequences of the D2HGDH and SLC25A1 genes.

CONCLUSIONMutation of the L2HGDH gene probably underlies the 2-hydroxyglutaric aciduria in this family.

Alcohol Oxidoreductases ; genetics ; Base Sequence ; Brain ; diagnostic imaging ; Brain Diseases, Metabolic, Inborn ; diagnostic imaging ; enzymology ; genetics ; Child ; Female ; Humans ; Male ; Molecular Sequence Data ; Mutation ; Pedigree ; Radiography ; Young Adult