Urine Gas Chromatography-mass Spectrometry Research Articles

Analysis of clinical features and genetic variants in three children with late-onset Multiple acyl-Coenzyme A dehydrogenase deficiency

To explore the clinical characteristics and genetic variants in three children with late-onset Multiple acyl-Coenzyme A dehydrogenase deficiency (MADD type Ⅲ). Clinical data of three children diagnosed with late-onset MADD at the Children's Hospital Affiliated to Zhengzhou University between March 2020 and March 2022 were retrospectively analyzed. All children were subjected to whole exome sequencing (WES), and candidate variants were verified by Sanger sequencing. All children had received improved metabolic therapy and followed up for 1 ~ 3 years. The children had included 2 males and 1 female, and aged from 2 months to 11 years and 7 months. Child 1 had intermittent vomiting, child 2 had weakness in lower limbs, while child 3 had no symptom except abnormal neonatal screening. Tandem mass spectrometry of the three children showed elevation of multiple acylcarnitines with short, medium and long chains. Children 1 and 2 showed increased glutaric acid and multiple dicarboxylic acids by urine Gas chromatography-mass spectrometry (GC-MS) analysis. All children were found to harbor compound heterozygous variants of the ETFDH gene, including a paternal c.1211T>C (p.M404T) and a maternal c.488-22T>G variant in child 1, a paternal c.1717C>T (p.Q573X) and a maternal c.250G>A (p.A84T) variant in child 2, and a paternal c.1285+1G>A and maternal c.629A>G (p.S210N) variant in child 3. As for the treatment, high-dose vitamin B2, levocarnitine and coenzyme Q10 were given to improve the metabolism, in addition with a low fat, hypoproteinic and high carbohydrate diet. All children showed a stable condition with normal growth and development during the follow-up. The compound heterozygous variants of the ETFDH gene probably underlay the muscle weakness, remittent vomiting, elevated short, medium, and long chain acylcarnitine, as well as elevated glutaric acid and various dicarboxylic acids in the three children with type Ⅲ MADD.

206,977 newborn screening results reveal the ethnic differences in the spectrum of inborn errors of metabolism in Huaihua, China.

Inborn errors of metabolism (IEMs) are rare diseases caused by inherited defects in various biochemical pathways that strongly correlate with early neonatal mortality and stunting. Currently, no studies have reported on the incidence of IEMs of multi-ethnic groups in Huaihua, China. A total of 206,977 neonates with self-reported ethnicity who underwent IEM screening at Huaihua from 2015 to 2021 were selected for observation. Among them, 69 suspected IEM-positive neonates were referred for urine gas chromatography-mass spectrometry analysis, biochemical detection, next-generation sequencing, and Sanger sequencing. Sixty-nine newborns were diagnosed with IEMs, with an overall incidence of 1:3,000. The two most common disorders were 2-methylbutyryl glycinuria (1:7,137) and phenylalanine hydroxylase deficiency (1:22,997). Moreover, the incidence of IEMs in the minority ethnic group (Miao, Dong, Tujia and Yao) (1:1,852) was markedly higher than in the Han ethnic group (1:4,741). Some ethnic features variants were identified; NM_001609.4:c.1165A>G in the ACADSB gene for Miao and Dong ethnic groups, NM_014251.2:c.852_855del in the SLC25A13 gene for Miao ethnic groups. This study revealed the IEM incidence within the minority ethnic groups is markedly higher than among the Han nationality and the gene variant spectrum is dramatically different in Huaihua, China. Hence, It serves as a theoretical reference for the screening and diagnosing of neonatal IEMs of multi-ethnic groups in the Huaihua area, and across China.

Characteristics, differential diagnosis, individualized treatment, and prevention of hyperhomocysteinemia in newborns

ObjectivesThis study aimed to investigate the incidence rate, clinical phenotype, gene variation spectrum, and prognosis of neonatal hyperhomocysteinemia (HHcy) and explore its diagnosis, individualised treatment, and prevention strategies. MethodsWe screened 84722 neonates for HHcy using liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with biochemical detection, urine gas chromatography-mass spectrometry (GC-MS), and next-generation sequencing (NGS) for gene analysis to comprehensively differentiate and diagnose diseases. Results18 children (P1–P18) were diagnosed with methylmalonic acidemia (MMA) and HHcy, and fourteen known and one new variant of the MMACHC gene were found. Five children showed poor mental reactions, brain dysplasia, lethargy, hyperbilirubinemia, and jaundice, whereas the other 13 children had no evident abnormalities. These children were all cobalamin- and folic acid-reactive types, and they were mainly supplemented with cobalamin, L-carnitine, betaine, and folic acid. The mother of P12 had a prenatal diagnosis at the next pregnancy; the results showed that MMACHC gene was not pathogenic and she gave birth to a healthy baby. One child (P19) was diagnosed with methylenetetrahydrofolate reductase (MTHFR) deficiency, and one new mutation was detected in the MTHFR gene. Patient P19 showed congenital brain dysplasia, neonatal anaemia, and hyperbilirubinemia, and treatment consisted mainly of betaine and cobalamin supplementation. One child (P20) was confirmed to have methionine adenosyltransferase I (MAT I) deficiency but had no clinical manifestations. After treatment, all the children had a good prognosis. ConclusionThe incidence of neonatal HHcy in the Zibo area was 1/4236, and the common pathogenic variants were c.609G>A, c.80A>G, and c.482G>A in the MMACHC gene. Patients with HHcy can achieve a good prognosis if pathogenic factors and targeted treatment are identified. Gene analysis and prenatal diagnosis contribute to the early prevention of HHcy.

Clinical and Gene Analysis of Fatty Acid Oxidation Disorders Found in Neonatal Tandem Mass Spectrometry Screening.

To investigate the clinical and gene mutation characteristics of fatty acid oxidative metabolic diseases found in neonatal screening. A retrospective analysis was performed on 29,948 neonatal blood tandem mass spectrometry screening samples from January 2018 to December 2021 in our neonatal screening centre. For screening positive, recall review is still suspected of fatty acid oxidation metabolic disorders in children as soon as possible to improve the genetic metabolic disease-related gene detection package to confirm the diagnosis. All diagnosed children were followed up to the deadline. Among 29,948 neonates screened by tandem mass spectrometry, 14 cases of primary carnitine deficiency, six cases of short-chain acyl coenzyme A dehydrogenase deficiency, two cases of carnitine palmitoyltransferase-I deficiency and one case of multiple acyl coenzyme A dehydrogenase deficiency were recalled. Except for two cases of multiple acyl coenzyme A dehydrogenase deficiency that exhibited [manifestations], the other 21 cases were diagnosed pre-symptomatically. Eight mutations of SLC22A5 gene were detected, including c.51C>G, c.403G>A, c.506G>A, c.1400C>G, c.1085C>T, c.706C>T, c.1540G>C and c.338G>A. Compound heterozygous mutation of CPT1A gene c.2201T>C, c.1318G>A, c.2246G>A, c.2125G>A and ETFA gene c.365G>A and c.699_701delGTT were detected, and new mutation sites were found. Neonatal tandem mass spectrometry screening is an effective method for identifying fatty acid oxidative metabolic diseases, but it should be combined with urine gas chromatography-mass spectrometry and gene sequencing technology. Our findings enrich the gene mutation profile of fatty acid oxidative metabolic disease and provide evidence for genetic counselling and prenatal diagnosis in families.

Identification of gene mutations in six Chinese patients with maple syrup urine disease.

Background: Maple syrup urine disease (MSUD) is a rare autosomal recessive amino acid metabolic disease. This study is to identify the pathogenic genetic factors of six cases of MUSD and evaluates the application value of high-throughput sequencing technology in the early diagnosis of MUSD. Methods: Clinical examination was carried out for patients and used blood tandem mass spectrometry (MS/MS), urine gas chromatography-mass spectrometry (GC/MS), and the application of high-throughput sequencing technology for detection. Validate candidate mutations by polymerase chain reaction (PCR)-Sanger sequencing technology. Bioinformatics software analyzed the variants' pathogenicity. Using Swiss PDB Viewer software to predict the effect of mutation on the structure of BCKDHA and BCKDHB proteins. Result: A total of six MSUD patients were diagnosed, including four males and two females. Nine variants were found in three genes of six MSUD families by high-throughput sequencing, including four missense mutations: c.659C>T(p.A220V), c.818C>T(p.T273I), c.1134C>G(p.D378E), and c.1006G>A(p.G336S); two non-sense mutations: c.1291C>T(p.R431*) and c.331C>T(p.R111*); three deletion mutations: c.550delT (p.S184Pfs*46), c.718delC (p.P240Lfs*14), and c.795delG (p.N266Tfs*64). Sanger sequencing's results were consistent with the high-throughput sequencing. The bioinformatics software revealed that the mutations were harmful, and the prediction results of Swiss PDB Viewer suggest that variation affects protein conformation. Conclusion: This study identified nine pathogenic variants in the BCKDHA, BCKDHB, and DBT genes in six MSUD families, including two novel pathogenic variants in the BCKDHB gene, which enriched the genetic mutational spectrum of the disease. High-throughput sequencing is essential for the MSUD's differential diagnosis, early treatment, and prenatal diagnosis.

Clinical features and genetic analysis of a child with acute form of Tyrosinemia type I due to a novel variant of FAH gene

To analyze the clinical phenotype and genetic basis for a child with acute form of tyrosinemia type I (TYRSN1). A child with TYRSN1 who presented at the Gansu Provincial Maternal and Child Health Care Hospital in October 2020 was selected as the subject. The child was subjected to tandem mass spectrometry (MS-MS) and urine gas chromatography-mass spectrometry (GC-MS) for the detection of inherited metabolic disorders, in addition with whole exome sequencing (WES). Candidate variants were validated by Sanger sequencing. The child's clinical features included abdominal distension, hepatomegaly, anemia and tendency of bleeding. By mass spectrometry analysis, her serum and urine tyrosine and succinylacetone levels have both exceeded the normal ranges. WES and Sanger sequencing revealed that she has harbored c.1062+5G>A and c.943T>C (p.Cys315Arg) compound heterozygous variants of the FAH gene, which were inherited from her father and mother, respectively. Among these, the c.943T>C was unreported previously. Considering her clinical phenotype and result of genetic testing, the child was diagnosed with TYRSN1 (acute type). The compound heterozygous variants of the FAH gene probably underlay the disease in this child. Above finding has further expanded the spectrum of FAH gene variants, and provided a basis for accurate treatment, genetic counseling and prenatal diagnosis for her family.

Inborn Errors of Ketogenesis: Novel Variants, Clinical Presentation, and Follow-Up in a Series of Four Patients.

Inborn errors of ketogenesis are rare disorders that result in acute and fulminant decompensation during lipolytic stress, particularly in infants and children. These include mitochondrial 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase (HMGCS) deficiency and HMG-CoA lyase (HMGCL) deficiency. In this series, we describe the clinical, biochemical, and molecular profiles of four patients along with dietary interventions and their outcomes on a long-term follow-up. Two patients each of HMGCS and HMGCL deficiency were evaluated with clinical history, biochemical investigations, including tandem mass spectrometry (TMS) and urine gas chromatography-mass spectrometry (GCMS). Molecular analysis was performed by whole-exome sequencing, as well as exon array validated by long-range polymerase chain reaction. All individuals were diagnosed with acute metabolic decompensation in the early infancy period except one with HMGCL deficiency who had the first presentation at 5 years of age. Central nervous system manifestations, severe metabolic acidosis, hyperammonemia, hypoglycemia with a normal lactate, and absence of urinary ketones were observed in all the affected individuals. The disorder was life-threatening in three individuals and one succumbed to the illness. TMS was nonspecific and urine GCMS revealed dicarboxylic aciduria in HMGCS deficiency. Both the patients with HMGCL deficiency demonstrated elevated 3 hydroxyisovaleryl carnitine levels in TMS and metabolites of leucine degradation in urine GCMS. We identified five novel variants that included a large deletion involving exon 2 in HMGCL gene. There was no evidence of long-term neurological sequelae in the living individuals. Diet with moderation of fat intake was followed in two individuals with HMGCS deficiency. Low leucine and protein diet with moderation of fat intake was followed in the individual with HMGCL deficiency. All affected individuals are thriving well with no further major metabolic decompensation.

Clinical characteristics and related gene mutations of infants with short-chain acyl-CoA dehydrogenase deficiency by neonatal screening in Beijing.

To investigate the clinical characteristics of infants with short-chain acyl-CoA dehydrogenase deficiency (SCADD) and related gene mutations in Beijing. The acylcarnitine levels in the blood samples of 100 603 neonates in Beijing during August 2014 and March 2022 were measured by tandem mass spectrometry (MS/MS). The suspected SCADD neonates were rechecked by MS/MS, urine gas chromatography-mass spectrometry (GC/MS) and next-generation sequencing (NGS) for diagnosis. The clinical, biochemical and gene mutation characteristics of infants with SCADD were analyzed; the growth and intellectual development of these patients were observed regularly. Among 100 603 live births, the elevated C4 concentration or elevated C4/C3 ratio were detected in the initial screening from 196 neonates, and 131 were recalled. Five cases of SCADD were diagnosed with an incidence rate of 4.97/100 000 (1/20 121). There was no significant abnormality in clinical manifestations, however, the blood butyrylcarnitine (C4) level and the ratio of C4 to propionylcarnitine (C3) were raised in all diagnosed cases. Urinary organic acids were analyzed in 4 cases, all of whom had increased ethyl malonate acid levels. Seven mutations were detected in the ACADS gene, all of which were known missense mutations. One patient had homozygous mutation, and the others showed compound heterozygous mutations. No clinical symptoms were observed, and the physical and intellectual development was normal in all patients at a median age of 33 (4-40) months during follow-up. The incidence rate of SCADD was 1/20 121 in Beijing. Neonates with early diagnosis and without clinical symptoms usually have good prognosis.

Succinyl-CoA:3-ketoacid CoA transferase (SCOT) deficiency presenting as ketosis with hyperglycemia: A case report

We describe a case of previously normal 22-month-old male who presented with vomiting, loose motions, lethargy, and seizures for 1 day. He had high anion gap metabolic acidosis, hyperglycemia, and ketosis managed elsewhere as diabetic ketoacidosis. Early management included hemodynamic stabilization, mechanical ventilation, correction of metabolic acidosis, seizure control, and later peritoneal dialysis. He was finally diagnosed with succinyl CoA 3 ketoacid transferase deficiency, a disorder of ketone metabolism usually presents with metabolic acidosis, ketosis, and hypoglycemia. Most cases present during the neonatal period (50%) and remain up to 20 months of age. The pathognomic finding is a nonspecific elevation on ketones in urine gas chromatography–mass spectrometry. Genomic sequencing is confirmatory.

Gene diagnosis and pedigree analysis of two Han ethnicity families with propionic acidemia in Fujian.

Propionic acidemia is associated with pathogenic variants in PCCA or PCCB gene. We investigated the potential pathogenic variants in PCCA or PCCB genes in Fujian Han population.Two probands and their families of Han ethnicity containing two generations were subject to newborn screening using tandem mass spectrometry, followed by diagnosis using urine gas chromatography mass spectrometry. Sanger sequencing was used to identify potential mutations in PCCA and PCCB genes.Compound heterozygous variants were identified in PCCB gene in two siblings of the first family, the youngest girl showed a novel missense variant c.1381G>C (p.Ala461Pro) in exon 13 and a heterozygous missense variant c.1301C>T (p.Ala434Val) in exon 13, which were inherited respectively from their parents. The oldest boy is a carrier with a novel missense variant c.1381G>C (p.Ala461Pro) in exon 13 which were inherited from his father. In the second family, c.1535G>A homozygous mutations were identified in the baby girl, which were inherited respectively from their parents. In silico analysis, several different types of bioinformatic software were utilized, which predicted that the novel variant c.1381G>C in PCCB gene was damaged. According to ACMG principle, the missense variant c.1381G>C (p.Ala461Pro) in exon 13 was a Variant of Undetermined Significance (VUS).One novel missense variant and two missense variants in PCCB gene were identified in the study. The novel variant of PCCB gene identified VUS was identified for the first time in the Chinese population, which enriched the mutational spectrum of PCCB gene.

Clinical Characteristics, Molecular Profile, and Outcomes in Indian Patients with Glutaric Aciduria Type 1.

Glutaric acidemia type 1 (GA-1, OMIM 231670) is an autosomal recessive inborn error of metabolism caused by the deficiency of glutaryl-coenzyme A (CoA) dehydrogenase with most children presenting in infancy with encephalopathy, dystonia, and macrocephaly. In this article, we presented the clinical characteristics, molecular profile, and outcomes in 29 unrelated families with affected children (30 cases total). The mean age at onset of illness was 10 months (±14.58), whereas the mean age at referral for molecular diagnosis was 29.44 months (±28.11). Patients were residents of nine different states of India. Clinical presentation varied from acute encephalitis followed by neuroregression and chronic/insidious developmental delay. Neurological sequelae varied from asymptomatic (no sequelae, 2 patients) to moderate (5 patients) and severe (23 patients) sequelae. All patients underwent blood tandem mass spectrometry (TMS on dried blood spots) and/or urine gas chromatography mass spectrometry (GCMS). Neuroimaging demonstrated batwing appearance in 95% cases. Sanger's sequencing of GCDH , covering all exons and exon-intron boundaries, was performed for all patients. Variants identified include 15 novel coding variants: p.Met100Thr, p.Gly107Ser, p.Leu179Val, p.Pro217Ser, p. Phe236Leufs*107, p.Ser255Pro, p.Met266Leufs*2, p.Gln330Ter, p.Thr344Ile, p.Leu345Pro, p.Lys377Arg, p.Leu424Pro, p.Asn373Lys, p.Lys377Arg, p.Asn392Metfs*9, and nine known genetic variants such as p.Arg128Gln, p.Leu179Arg, p.Trp225Ter, p.Met339Val, p.Gly354Ser, p.Arg402Gln, p.Arg402Trp, p.His403Tyr, and p.Ala433Val (Ensembl transcript ID: ENST00000222214). Using in silico analysis, genetic variants were shown to be affecting the residues responsible for homotetramer formation of the glutaryl-CoA dehydrogenase protein. Treatment included oral carnitine, riboflavin, protein-restricted diet, lysine-deficient special formulae, and management of acute crises with intravenous glucose and hydration. However, the mortality (9/30, 27.58%) and morbidity was high in our cohort with only two patients affording the diet. Our study is the largest multicentric, genetic variant-proven series of glutaric aciduria type 1 from India till date.

Residual Adrenal Function in Autoimmune Addison’s Disease—Effect of Dual Therapy With Rituximab and Depot Tetracosactide

ContextIn autoimmune Addison’s disease (AAD), exogenous glucocorticoid (GC) therapy is an imperfect substitute for physiological GC secretion. Patients on long-term steroid replacement have increased morbidity, reduced life expectancy, and poorer quality of life.ObjectiveThe objective of this article is to restore adrenocortical steroidogenic function in recent-onset AAD.DesignAn open-label, multicenter trial of immunotherapy and trophic stimulation in new-onset AAD was conducted. Serial measurement of serum and urine corticosteroids at baseline and throughout a 72-week follow-up period was performed.SettingThis study was conducted at theendocrine departments and clinical research facilities at 5 UK tertiary centers.PatientsThirteen participants (9 female, 4 male; age 19-64 years) were included with AAD confirmed by high adrenocorticotropin, low circulating cortisol (basal < 100 nmol/L or post-tetracosactide < 300 nmol/L), and positive serum 21-hydroxylase antibodies.InterventionAll participants received dual therapy with B-lymphocyte–depleting immunotherapy (rituximab 1 g given twice) and repeated depot tetracosactide (1 mg on alternate days for 12 weeks).Main Outcome MeasureRestoration of normal GC secretion (stimulated cortisol > 550 nmol/L) at week 48 was the main outcome measure.ResultsTen of 13 (77%) participants had detectable stimulated serum cortisol (26-265 nmol/L) at trial entry. Following intervention, 7 of 13 (54%) had an increase in stimulated cortisol measurement, with a peak response of 325 nmol/L at week 18 in 1 participant. Increased steroid metabolites, assayed by urine gas chromatography–mass spectrometry at week 12 and week 48, was detected in 8 of 13 (62%) individuals, reflecting an increase in endogenous steroidogenesis. Four of 13 had residual adrenal function at 72 weeks.ConclusionCombined treatment with rituximab and depot tetracosactide did not restore normal adrenal function. Nevertheless, adrenocortical plasticity is demonstrated in some patients, and this has the potential to be exploited to improve adrenal function.

A 21st Century Problem: Cannabis Toxicity in a 13-Month-Old Child

BackgroundCannabis is one of the most abused drugs worldwide, with more than 20 million users in the United States (US). As access to cannabis products increases with expanding US legislation and decriminalization of marijuana, emergency physicians must be adept in recognizing unintentional cannabis toxicity in young children, which can range from altered mental status to encephalopathy and coma. Case ReportWe report the case of a 13-month-old female presenting with self-limiting altered mental status and lethargy, with a subsequent diagnosis of tetrahydrocannabinol exposure on confirmatory urine gas chromatography-mass spectrometry. Why Should an Emergency Physician Be Aware of This?Considering caretakers rarely report possible cannabis exposure, history-taking must review caretakers’ medicinal and recreational drug exposures to prevent inadvertently missing the diagnosis. In the young child with altered mental status, prompt urine screening for cannabinoid detection can prevent further invasive and costly diagnostic investigations, such as brain imaging and lumbar puncture.

A rare case of beta-ketothiolase deficiency in identical twins

Betaketothiolase deficiency is a rare defect of isoleucine and ketone body metabolism which manifests as severe metabolic acidosis following common viral illnesses. A set of 1 year, 8 month-old identical male twins presented with similar symptoms in different time frames. Both of them had severe metabolic acidosis, hypoglycemia, and altered sensorium. Both twins tested positive for beta-ketothiolase deficiency by urine gas chromatography-mass spectrometry. The children responded to symptomatic treatment and are now growing well on a protein-restricted diet. Beta-ketothiolase deficiency is a rare disorder of amino acid metabolism with a favorable outcome if preventive measures are taken early.

Screening for newborn organic aciduria in Zhejiang province:prevalence, outcome and follow-up

To analyze the results and follow up data of screening for newborn organic aciduria in Zhejiang province. The results and follow-up data of 1 861 262 newborns from Zhejiang province undergoing screening for organic aciduria during January 2009 and December 2016 were retrospectively analyzed. The acylcarnitine spectrum in urine samples was detected by tandem mass spectrum (MS/MS) and the positive patients were confirmed by urine gas chromatography mass spectrometry and/or gene analysis. Ninety two cases of organic aciduria were confirmed with a prevalence of 1:20 200. Among 40 cases of methylmalonic academia (MMA), 13 (32.5%) were of MMA simple type and 27 (67.5%) were combined type. Genetic analysis showed 6 cases of MUT type and 1 case of CblB type out of 7 patients with MMA simple type, 10 cases of CblC and 1 case of CblF out of 11 patients with combined type, respectively. Six patients had propionic academia with a prevalence of 1:310 200, 7 had isovaleric academia (1:265 900), 6 had glutaric academia type 1 (1:310 200), 27 had 3-methylcrotonyl-CoA carboxylase deficiency (MCC, 1:68 900), 1 had 3-hydroxy-3-methylglutaric aciduria (1:1 861 300), 2 had β-ketothiolase deficiency (1:960 600), and 3 had biotinidase deficiency/holocarboxylase synthetase deficiency (1:620 400). Thirty-one patients had a disease onset at neonatal period, and 15 at post-neonatal period. Thirty-three patients had brain involvements or cranial imaging disorders. Three patients with MMA had kidney diseases or heomlytic uremic syndrome, and 3 had myocardial impairments. Twenty patients died during the follow-up. MMA is the most common newborn organic aciduria in Zhejiang province. Except MCC, most organic aciduria may lead to metabolism decompensation, complications or even death.

Value of albumin in diagnosis of neonatal intrahepatic cholestasis caused by citrin deficiency

Objective: To investigate the clinical value of albumin (Alb) in the diagnosis of neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD). Methods: A retrospective analysis was performed for the clinical data of 90 children with NICCD who visited Children's Hospital of Fudan University from January 2007 to December 2014, and according to the content of Alb, these children were divided into Alb < 30 g/L (LA) group with 20 children and Alb ≥30 g/L (NA) group with 70 children. The clinical manifestations, results of laboratory examination, results of blood tandem mass spectrometry and urine gas chromatography-mass spectrometry, and gene detection results were compared between the two groups. The t-test and the chi-square test were used for statistical analysis.. Results: There were significant differences between the LA group and the NA group in splenomegaly degree (3.28±1.95 cm vs 1.92±1.06 cm, P = 0.030), aspartate aminotransferase/alanine aminotransferase ratio [3.15 (0.38-5.93) vs 2.14 (0.26-6.67), P = 0.010], activated partial thromboplastin time (53.27±11.68 s vs 45.06±9.79 s, P = 0.003), and international normalized ratio (1.92±1.35 vs 1.29±0.33, P = 0.001). The SLC25A13 mutation I 851_854del4 was associated with Alb (χ2 = 4.76, P = 0.025). Conclusion: As for the children with Alb < 30g/L who are highly suspected of having NICCD, SLC25A13 gene detection and blood/urine mass spectrometry should be performed as early as possible, in order to initiate intervention treatment as soon as possible, prevent and treat complications, and improve prognosis.

Detection of inborn errors of metabolism using GC-MS: over 3 years of experience in southern China.

Inborn errors of metabolism (IEM) have been detected worldwide using gas chromatography mass spectrometry (GC-MS) since the 1980s, but few related reports exist on the incidence, spectrum, and clinical presentation features of IEM in southern China. From January 2009 to March 2012, 16,075 urine samples were collected from patients who were highly suspected of having IEM in Guangzhou Women and Children's Medical Center. The specimens were evaluated using GC-MS. We diagnosed 303 cases of IEM by urine GC-MS analysis, including 197 cases with amino acid disorders, 86 cases with organic acidurias (OAs), 10 cases with fatty acid oxidative (FAO) disorders, and 10 cases with peroxisomal disorders. Neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) was the most common (153 cases), followed by methylmalonic aciduria (48 cases), urea cycle disorders (21 cases), phenylketonuria (20 cases), propionic aciduria (11 cases), X-linked adrenoleukodystrophy (10 cases), multiple carboxylase deficiency (8 cases), glutaric aciduria type I (7 cases), isovaleric aciduria (6 cases), glutaric aciduria type II (4 cases), short-chain acyl-CoA dehydrogenase deficiency (4 cases), 3-hydroxy-3-methylglutaric aciduria (3 cases), maple syrup urine disease (2 cases), very long-chain acyl-CoA dehydrogenase deficiency (1 case), malonic aciduria (1 case), mevalonic aciduria (1 case), Canavan disease (1 case), lysine protein intolerance (1 case), and medium-chain acyl-CoA dehydrogenase deficiency (1 case). The clinical and laboratory features of IEM are neurologic signs, jaundice, metabolic acidosis, ketotic hypoglycemia, and hyperammonemia. In our study, GC-MS provided a diagnostic clue to OAs, amino acid disorders, FAO, and peroxisomal disorders. Urease pretreatment is useful for the diagnosis of NICCD. In southern China, the majority of IEM were amino acid disorders and organic acid disorders. FAO disorders were relatively rare, which we need to investigate further.

Amphetamine Positive Urine Toxicology Screen Secondary to Atomoxetine

The aim of this paper is to report the first case of atomoxetine leading to false-positive urine drug screen. An otherwise healthy 27-year-old female with a history of attention deficit hyperactivity disorder (ADHD) treated with atomoxetine had an acute onset tonic-clonic seizure. On arrival to the hospital, a urine toxicological drug screen with immunochemical cloned enzyme donor immunoassay (CEDIA) was performed. Results were positive for amphetamines; however, the presence of these substances could not be confirmed with urine gas chromatography-mass spectrometry (GC-MS). She denied any illicit drug use, herbal medications, or supplements, and her other prescription medications have not been previously known to cause a false-positive result for amphetamines. While stimulant treatments for ADHD could certainly result in a positive result on urine screen for amphetamines, there have been no reports of false-positive results for amphetamines secondary to patients using atomoxetine. We implicate atomoxetine, and/or its metabolites, as a compound or compounds which may interfere with urine drug immunoassays leading to false-positive results for amphetamines CEDIA assays.

Spice: A New “Legal” Herbal Mixture Abused by Young Active Duty Military Personnel

ABSTRACT Spice is an herbal mixture smoked for euphoria and mixed with synthetic cannabinoids that are undetected on urine drug screens. Spice use has increased in the military because it is considered legal and is not detected on urine drug screen. The authors describe 3 cases of Spice use in military members. Case 1: 19-year-old male presented with paranoia, agitation, and visual hallucinations after smoking the “Space” brand of Spice. Urine thin-layer chromatography (TLC) and gas chromatography–mass spectrometry (GC-MS) were negative. Case 2: 19-year-old female presented with sedation, amnesia, and agitation. She smoked the “Space” brand. She was alert within 3 hours of arrival. Urine GC-MS detected levorphanol. Case 3: 23-year-old male presented with delusions and paranoia. He complained of “monsters on his back.” His symptoms improved in the emergency department (ED). His urine TLC and GC-MS were negative. All cases were admitted and evaluated by a toxicologist; all 3 had their history corroborated by family or friends, or with drug paraphernalia. Spice is a new herbal mixture that is increasingly used in the military. Expected effects are similar to cannabis, but may include more paranoia and hallucinations, and may differ for each brand.

GHB Urine Concentrations After Single-Dose Administration in Humans

Gamma-hydroxybutyric acid (GHB) is used as an illicit drug and is implicated in drug-facilitated sexual assault, but it also has some therapeutic uses. Detection of GHB in urine is important for forensic testing and could be of clinical benefit in overdose management. Urine GHB concentration-time profiles have not been well-characterized or correlated with doses used therapeutically. GHB levels were measured by gas chromatography-mass spectrometry in urine collected over 24 h from 16 adults administered single doses of 50 mg/kg GHB (Xyrem) alone and combined with 0.6 g/kg ethanol. Peak GHB urine concentrations averaged 150-200 mg/L and occurred in the 0-3 h urine collection. Significant variability in GHB urine levels between individuals was observed. Caucasians had lower urine concentrations than other races/ethnicities (p = 0.03). Men had lower GHB levels than women in the first 3 h after dosing (p = 0.038). Coingestion of ethanol did not significantly affect renal clearance of GHB, but urine GHB concentrations were lower in the first 3 h when ethanol and GHB were coingested (p = 0.039). At a proposed cut-off of 10 mg/L to distinguish endogenous versus exogenous GHB levels, 12.5% of the samples collected from 3 to 6 h, 81.3% of samples collected from 6 to 12 h, and 100% of urine specimens collected from 12 to 24 h were below this level. We conclude that the detection time for GHB in urine may be shorter than the previously reported 12-h window in some people taking therapeutic doses of GHB.