Hypermethioninemia due to methionine adenosyltransferase I/III deficiency and brain damage.

Background And Objectives: Methionine adenosyltransferase I/III deficiency used to be considered a relatively benign disease. This study aims to elucidate the clinical characteristics of methionine adenosyltransferase I/III deficiency patients with neurological manifestations.

Methods: The clinical data, blood amino acids, plasma total homocysteine, gene variants, brain imaging, treatments and outcomes of 15 patients with methionine adenosyltransferase I/III deficiency were retrospectively analyzed.

Clinical features and CPS1 variants in Chinese patients with carbamoyl phosphate synthetase 1 deficiency.

Background: Carbamoyl phosphate synthetase 1 (CPS1) deficiency (OMIM 237300), an autosomal recessive rare and severe urea cycle disorder, is associated with hyperammonemia and high mortality.

Methods: Herein we present 12 genetic variants identified in seven clinically well-characterized Chinese patients with CPS1 deficiency who were admitted to the Children's Medical Center of Peking University First Hospital from September 2014 to August 2023.

Results: Seven patients (two male and five female patients including two sisters) experienced symptoms onset between 2 days and 13 years of age, and they were diagnosed with CPS1 deficiency between 2 months and 20 years.

The utility of methylmalonic acid, methylcitrate acid, and homocysteine in dried blood spots for therapeutic monitoring of three inherited metabolic diseases.

Backgroud: Routine metabolic assessments for methylmalonic acidemia (MMA), propionic acidemia (PA), and homocysteinemia involve detecting metabolites in dried blood spots (DBS) and analyzing specific biomarkers in serum and urine. This study aimed to establish a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous detection of three specific biomarkers (methylmalonic acid, methylcitric acid, and homocysteine) in DBS, as well as to appraise the applicability of these three DBS metabolites in monitoring patients with MMA, PA, and homocysteinemia during follow-up.

Methods: A total of 140 healthy controls and 228 participants were enrolled, including 205 patients with MMA, 17 patients with PA, and 6 patients with homocysteinemia.

Clinical features and ALDH5A1 gene findings in 13 Chinese cases with succinic semialdehyde dehydrogenase deficiency.

Background And Aims: To investigate the clinical features, ALDH5A1 gene variations, treatment, and prognosis of patients with succinic semialdehyde dehydrogenase (SSADH) deficiency.

Materials And Methods: This retrospective study evaluated the findings in 13 Chinese patients with SSADH deficiency admitted to the Pediatric Department of Peking University First Hospital from September 2013 to September 2023.

Results: Thirteen patients (seven male and six female patients; two sibling sisters) had the symptoms aged from 1 month to 1 year.

Case report: An asymptomatic mother with an inborn error of cobalamin metabolism (cblC) detected through high homocysteine levels during prenatal diagnosis.

Background: The most common disorder of the intracellular cobalamin metabolism pathway is the combined methylmalonic acidemia and homocysteinemia, cblC type (cblC). There is a variation in its clinical spectrum ranging from severe neonatal-onset forms that are highly fatal to later-onset forms which are milder. In this study, the first case of an asymptomatic Chinese woman with a defect in congenital cobalamin (cblC type) metabolism at prenatal diagnosis due to elevated homocysteine level is identified.

Visible-Light-Promoted Direct C3-H Cyanomethylation of 2-Indazoles.

The efficient visible-light-promoted cyanomethylation of 2-indazoles in the presence of Ir(ppy) as the photocatalyst and bromoacetonitrile as the cyanomethyl radical source was achieved under mild conditions, providing a series of C3-cyanomethylated derivatives in good yields.

Late-onset cblC deficiency around puberty: a retrospective study of the clinical characteristics, diagnosis, and treatment.

Background: cblC deficiency is the most common type of methylmalonic aciduria in China. Late-onset patients present with various non-specific symptoms and are usually misdiagnosed. The purpose of this study is to investigate the clinical features of patients with late-onset cblC deficiency and explore diagnosis and management strategies around puberty.

[Factors affecting phenotypes in the patients with MMACHC gene c.609G>A homozygous variant cblC type methylmalonic acidemia combined with homocysteinuria].

Objective: To investigate the factors affecting phenotypes in the patients of methylmalonic acidemia combined with homocysteinemia cblC type with MMACHC c.609G>A homologous variant.

Methods: A retrospective study on the clinical manifestations, complications, treatment, and outcome in 164 patients of cblC type with MMACHC c.

Comparing amniotic fluid mass spectrometry assays and amniocyte gene analyses for the prenatal diagnosis of methylmalonic aciduria.

Background: Methylmalonic aciduria (MMA), a rare inherited disorder, is the most common organic aciduria in China, and prenatal diagnosis has contributed to its prevention. However, the prenatal diagnosis of MMA using cultured amniocytes or chorionic villi to detect gene mutations is exclusively applicable to families with a definite genetic diagnosis. To evaluate the reliability of mass spectrometry assays for the prenatal diagnosis of MMA, we conducted a retrospective study of our 10 years' experience.

Analysis of the relationship between phenotypes and genotypes in 60 Chinese patients with propionic acidemia: a fourteen-year experience at a tertiary hospital.

Background: Propionic acidemia is a severe inherited metabolic disorder, caused by the deficiency of propionyl-CoA carboxylase which encoded by the PCCA and PCCB genes. The aim of the study was to investigate the clinical features and outcomes, molecular epidemiology and phenotype-genotype relationship in Chinese population.

Methods: We conducted a retrospective study of 60 Chinese patients diagnosed at Peking University First Hospital from 2007 to 2020.

Analysis of 70 patients with hydrocephalus due to cobalamin C deficiency.

Objective: To analyze the clinical characteristics of patients with hydrocephalus secondary to cobalamin C (cblC) deficiency and to discuss the optimal strategies for assessing and treating such patients by performing clinical and laboratory studies in 70 patients.

Methods: A total of 1,211 patients were clinically diagnosed with methylmalonic acidemia (MMA) from 1998 to 2019. Among them, cblC deficiency was confirmed in 70 patients with hydrocephalus by brain imaging and biochemical and genetic analysis.

Variable phenotypes and outcomes associated with the MMACHC c.609G>A homologous mutation: long term follow-up in a large cohort of cases.

Background: Cobalamin C deficiency (cblC) caused by the MMACHC mutations is the most common type of the disorders of intracellular cobalamin metabolism. While the c.609G > A mutation is most frequent in Chinese cblC patients, its correlation with phenotype has not been delineated.

Eleven novel mutations and clinical characteristics in seven Chinese patients with thiamine metabolism dysfunction syndrome.

Thiamine metabolism dysfunction syndrome (THMD) comprises a group of clinically and genetically heterogeneous encephalopathies with autosomal recessive inheritance. Four genes, SLC19A3, SLC25A19, SLC19A2, and TPK1, are associated with this disorder. This study aimed to explore the clinical, biochemical and molecular characteristics of seven Chinese patients with THMD.

Reduced 24-h Sodium Excretion Is Associated With a Disturbed Plasma Acylcarnitine Profile in Vasovagal Syncope Children: A Pilot Study.

To investigate if the low sodium intake is associated with the plasma carnitine and acylcarnitine profile in children with vasovagal syncope (VVS). Twenty-six children suffering from VVS were recruited in the present study and divided into a group of low urinary sodium excretion or a group of normal urinary sodium excretion according to the excretion of 24-h urinary sodium <3 or 3-6 g, respectively. The excretion of 24-h urinary sodium was detected with ion-selective electrode approach.

Mutations of , Encoding Microtubule-Actin Crosslinking-Factor 1, Cause Spectraplakinopathy.

As a member of spectraplakin family of cytoskeletal crosslinking proteins, microtubule-actin crosslinking factor 1 (MACF1) controls cytoskeleton network dynamics. Knockout of in mice resulted in the developmental retardation and embryonic lethality. Spectraplakinopathy type I, a novel neuromuscular condition characterized by periodic hypotonia, lax muscles, joint contracture, and diminished motor skill, was reported to be associated with heterozygous genomic duplication involving the loci, with incomplete penetrance and highly variable clinical presentation in a single pedigree.

One potential hotspot ACADVL mutation in Chinese patients with very-long-chain acyl-coenzyme A dehydrogenase deficiency.

Very long-chain acyl-coenzyme A dehydrogenase deficiency (VLCAD deficiency), a rare autosomal recessive disorder, is characterized by hypoketotic hypoglycemia, cardiomyopathy, liver damage, and myopathy. VLCAD deficiency is caused by defects of ACADVL gene, which encodes VLCAD protein. The aim of this study was to determine the clinical, biochemical, prognosis and mutation spectrum of patients with VLCAD deficiency in mainland China.

A study on a cohort of 301 Chinese patients with isolated methylmalonic acidemia.

Methylmalonic acidemia (MMA) is the most common organic acidemia in China. This study aimed to characterise the genotypic and phenotypic variabilities, and the molecular epidemiology of Chinese patients with isolated MMA. Patients (n = 301) with isolated MMA were diagnosed by clinical examination, biochemical assays, and genetic analysis.

Eight novel mutations detected from eight Chinese patients with isovaleric acidemia.

Background: Isovaleric acidemia (IVA), a rare autosomal recessive disorder in leucine metabolism caused by defected IVD gene, is characterized by episodes of acute metabolic crisis and psychomotor development retardation. This study aimed to determine the clinical, biochemical, and mutation spectrum of patients with IVA from mainland China.

Methods: Eight patients (three boys and five girls) from eight unrelated families were collected, IVD gene mutations and phenotypes were examined.

Mutation Hot Spot Region in the HOGA1 Gene Associated with Primary Hyperoxaluria Type 3 in the Chinese Population.

Background: Primary hyperoxaluria type 3 (PH3) is a rare autosomal recessive disorder that affects glyoxylate metabolism. PH3 is caused by defects in 4-hydroxy-2-oxoglutarate aldolase, which is encoded by the HOGA1 gene. However, only 3 cases of PH3 have been described in Asians until today.

Medium-chain acyl-coenzyme A dehydrogenase deficiency: Six cases in the Chinese population.

Background: Medium-chain acyl-coenzyme A dehydrogenase deficiency (MCADD) is a rare autosomal recessive disorder that affects the degradation of medium-chain fatty acids. Few cases of MCADD have been documented to date in mainland China.

Methods: Medium-chain acyl-coenzyme A dehydrogenase deficiency was diagnosed in six patients (three girls and three boys) from six unrelated Chinese families at ages ranging from 10 days to 3 years old.

Patients with cobalamin G or J defect missed by the current newborn screening program: diagnosis and novel mutations.

Cobalamin G (cblG) and cobalamin J (cblJ) defects are rare disorders of cbl metabolism caused by MTR and ABCD4 mutations, respectively. Patients with atypical biochemical features can be missed by current newborn screening using tandem mass spectrometry (MS/MS), in which total homocysteine (tHCY) in dried blood spots (DBS) is not a primary biomarker. Two Chinese patients suspected of cbl defect but missed by newborn screening were studied.

[Reye syndrome and sudden death symptoms after oral administration of nimesulide due to upper respiratory tract infection in a boy].

A boy aged 6 years and 3 months developed upper respiratory tract infection and pyrexia 2 months ago and was given oral administration of nimesulide by his parents according to directions. Half an hour later, the boy experienced convulsions and cardiopulmonary arrest, and emergency examination found hypoketotic hypoglycemia, metabolic acidosis, significant increases in serum aminotransferases and creatine kinase, and renal damage. Recovery of consciousness and vital signs was achieved after cardiopulmonary resuscitation, but severe mental and movement regression was observed.

Further delineation of AGPAT2 and BSCL2 related congenital generalized lipodystrophy in young infants.

Background And Objectives: Congenital generalized lipodystrophy (CGL) is a rare autosomal recessive disorder with two major subtypes, which are caused by AGPAT2 and BSCL2 mutations. Our aim was to further investigate the genetic features and clinical characteristics of infant patients with CGL.

Patients And Methods: Three male infants and two female infants aged from one month to three months and unrelated with each other were involved in this study.

Clinical, Biochemical, and Genetic Findings of Cystinuria in Chinese Children.

Background: Cystinuria is a rare inherited renal stone disease caused by mutations in the SLC3A1 and SLC7A9 genes. The Chinese cystinuria phenotype and genotype have rarely been reported in the literature.

Methods: For this research, the clinical features and genetic etiology were analyzed in seven children, and the clinical characteristics were summarized.