Search Results (54)

Acyl-CoA dehydrogenase 9 deficiency is considered as a rare neuromuscular syndrome with an autosomal recessive transmission. The ACAD9 protein presents two essential functions, i.e., the limiting step enzyme of the fatty acid β-oxidation pathway and one of the complex’s compounds involved in the respiratory chain complex I assembly. Thus, loss-of-function mutations are known to convey mitochondrial cytopathologies. A patient with a mild and late-onset phenotype, suffering from exercise intolerance and hypertrophic cardiomyopathy, was diagnosed as a compound heterozygote of the ACAD9 gene. The first c.1240C> T p.Arg414Cys variant has been previously reported and is known to be responsible for ACAD9 deficiency. However, the second c.1636G> A p.Val546Met variant has never been described. The goal was to investigate the eventual pathogenicity of this new genetic variant. For this purpose, molecular cloning was generated to express the ACAD9 gene with the V546M variant in a cell line (ACAD9mut) and compared to cells expressing the wild-type ACAD9. Then, the mitochondrial respiration, ATP production, the mitochondrial network, and the oxidative phosphorylation’s composition were investigated to reveal the effects of the V546M variant. While avoiding to affect the amount of the respiratory chain’s complexes, the new ACAD9 variant was entirely responsible for reducing over 50% of the mitochondrial complex I activity. Full article

Multiple acyl-CoA dehydrogenase deficiency (MADD), also known as glutaric acidemia/glutaric aciduria type II (GA II), is an inborn error of fatty acid, amino acid, and choline metabolism. The chronic management of MADD involves both dietary fat and protein restriction to reduce the substrates of the dehydrogenases affected, the avoidance of prolonged fasting as in any fat metabolism disorder, and monitoring for potential complications. Due to its rarity, there is little published experience on the management of MADD in pregnancy. Herein, we report the successful management of a pregnancy in a patient with late-onset or type III MADD, with considerations for preconception, antepartum, intrapartum, and postpartum care. Full article

Background: Very-long-chain acyl-CoA dehydrogenase deficiency (VLCADD) is caused by biallelic pathogenic variants in ACADVL (acyl-CoA dehydrogenase very-long-chain), leading to impaired fatty acid oxidation and the accumulation of long-chain acylcarnitine. We report a single case of a two-year-old girl, whose neonatal metabolic screening revealed an acylcarnitine profile suggestive of VLCADD, with residual enzymatic activity of 19.8%. Methods: We performed ACADVL whole-gene sequencing. We then carried out an in silico analysis of the potential effects of the variants with dedicated tools, assessing splicing, RNA structure, RNA binding factors, and protein structure. We also conducted gene expression analysis. Results: Genetic testing identified her as compound heterozygous for the pathogenic ACADVL variant (NM_000018.3):c.848T>C, inherited from her mother, and for the two paternal variants, c.-64T>C in the basal promoter and c.957G>A, a synonymous substitution in exon 10. Gene expression analysis revealed reduced ACADVL mRNA levels in the proband’s blood cells but without abnormal isoform production. A decreased expression of the paternal allele carrying the 957A was also observed. Despite this significant reduction in mRNA levels, the underlying mechanism remains unclear. Conclusions: Although currently healthy, due to the VLCAD residual activity within the range associated with the mild form of the disease, the child might be at potential risk for metabolic decompensation or late-onset VLCADD. Our results indicated an allelic imbalance in mRNA expression and c.957G>A is identified as a hypomorphic allele. This suggests that deep ACADVL sequencing is a valuable tool for correlating genetic variants with enzymatic activity levels. Full article

The detection of elevated long-chain acylcarnitine levels, particularly C14:1 and the C14:1/C2 ratio, during neonatal screening may indicate very-long-chain acyl-CoA dehydrogenase deficiency (VLCADD), although similar findings can result from postnatal starvation. We investigated the relationship between false-positive results, postnatal weight loss, and subsequent growth. Additionally, we explored potential diagnostic markers of postnatal starvation. The following neonates from Oita Prefecture (April 2014–March 2024) were included in this study: patients identified as false-positive for VLCADD (n = 19), patients with VLCADD (n = 3), and children negative in mass screening who completed their 3-year-old health check-up (n = 30). The false-positive group exhibited significant weight loss at blood sampling for neonatal screening. An acylcarnitine analysis showed significant increases in various short- to long-chain fatty acids in the false-positive group, likely owing to enhanced fatty acid catabolism via β-oxidation. Elevation of a broad range of fatty acids and reduced amino acid levels seemed to be associated with significant weight loss at blood sampling. Full article

Background: Expanded Newborn Screening (ENS) allows the early identification of many inherited metabolic diseases (IMDs) for which timely treatment can modify the natural history. For most IMDs, diagnosis by ENS is pre-clinical. However, clinical symptoms may emerge for certain conditions before screening results become available. Methods: We describe six cases of patients with early-onset IMDs born between 2013 and 2023, who were admitted or transferred to Sant’Orsola University Hospital in Bologna (Italy). Results: Over the study period, 379,013 newborns underwent ENS in the Italian region of Emilia-Romagna. Excluding cases of congenital hypothyroidism, pre-clinical diagnoses from ENS were 410. In addition, six cases of IMD presented with early-onset clinical symptomatology, an antecedent to the outcome of newborn screening (incidence over 11 years of 1.58 cases per 100,000 infants). Among these patients, three were diagnosed with Urea Cycle Disorders (UCDs)—two with Citrullinemia type I (CIT1) and one with Argininosuccinic Acidemia (ASA); two were diagnosed with Methylmalonic Acidemia (MMA); and one was found to have Medium-Chain Acyl-CoA Dehydrogenase Deficiency (MCADD). Conclusions: Our 11-year experience with ENS has shown that clinical onset can occur between the second and fourth day of life, though rare. Even if dried blood spot (DBS) collection was performed 24–48 h after birth, the time required for sample transportation and processing would still delay result availability, making early intervention unlikely. Therefore, our experience supports performing ENS at 48–72 h, as currently implemented in Italy, while also highlighting the advantages and limitations of earlier screening. Full article

Very-long-chain acyl-CoA dehydrogenase deficiency (VLCADD) is due to a defect in metabolism of long-chain fatty acids. Infants with VLCADD may experience cardiomyopathy, hypoglycemia, or even death; thus, early detection and intervention is crucial. The spectrum of disease and natural variation in newborn metabolism, however, lead to overlap in acylcarnitine values between affected and unaffected individuals, which contributes to the difficulty in identifying true positive cases while minimizing false positive cases. VLCADD was added to the state of Wisconsin’s newborn screening (NBS) panel in 2000. A previous retrospective review of VLCADD screen positive cases identified between 2000 and 2014 resulted in a change to the screening algorithm. Following implementation, a reduction in the percentage of false positive screens from 25.3% to 20.4% was observed between 2015 and 2021. The overall PPV also decreased, from 37.2% to 28%, due to an increase in the number of carriers identified (27.5% of cases in 2000–2014 and 51.8% of cases in 2015–2021). A data review also identified three long-chain acylcarnitine elevations (C14:1, C14:1/C16, and C14:1/C2) that had statistically significant differences in concentrations in true positive populations versus false positive populations. Utilization of the C14:1, C14:1/C16, and C14:1/C2 values in newborn screening may provide clearer distinction between true positive and carrier populations and additionally increase the PPV of this screen. Full article

Carnitine plays an essential role in maintaining energy homeostasis and metabolic flexibility. Various medications, such as pivalate-conjugated antibiotics, valproic acid, and anticancer agents, can induce carnitine deficiency, inhibit the utilization of fatty acid, and contribute to the development of hypoglycemia. No studies have linked oral semaglutide to carnitine deficiency. Herein, we report the case of a 34-year-old male patient with multiple acyl-CoA dehydrogenase deficiency who developed carnitine deficiency attributable to salcaprozic acid sodium (SNAC) in oral semaglutide. The patient was diagnosed with type 2 diabetes mellitus at 32 years of age and was treated with semaglutide injections. Hypoglycemic symptoms appeared after switching to oral semaglutide, and the mean levels of blood-free carnitine significantly decreased. Liquid chromatography–tandem mass spectrometry analysis revealed a peak corresponding to the SNAC–carnitine complex (m/z 423.24) in the urine exclusively during the oral administration of semaglutide. The MS/MS spectra at m/z 423.24 contained peaks consistent with those of the SNAC and carnitine product ions. Our results suggest that through complexation with carnitine, SNAC may induce carnitine deficiency. Healthcare providers should monitor for carnitine deficiency when administering SNAC-containing medications to at-risk individuals. Furthermore, this case can raise more significant concerns about the potential impact of pharmaceutical excipients like SNAC on metabolic pathways. Full article

Living systems require energy to maintain their existence and perform tasks such as cell division. This energy is stored in several molecular forms in nature, specifically lipids, carbohydrates, and amino acids. At a cellular level, energy is extracted from these complex molecules and transferred to adenosine triphosphate (ATP) in the cytoplasm and mitochondria. Within the mitochondria, fatty acid β-oxidation (FAO) and oxidative phosphorylation (OXPHOS) are crucial metabolic processes involved in generating ATP, with defects in these pathways causing mitochondrial disease. Very long-chain acyl-CoA dehydrogenase deficiency (VLCADD) is a fatty acid β-oxidation disorder (FAOD) affecting 1 to 2 individuals per 100,000. Similar to other mitochondrial disorders, there is no cure for VLCADD, with symptomatic treatment comprising dietary management and supplementation with medium-chain fatty acids to bypass the enzyme deficiency. While this addresses the primary defect in VLCADD, there is growing evidence that other aspects of mitochondrial function are also affected in VLCADD, including secondary defects in OXPHOS function. Here, we review our current understanding of VLCADD with a focus on the associated biochemical and molecular defects that can disrupt multiple aspects of mitochondrial function. We describe the interactions between FAO proteins and the OXPHOS complexes and how these interactions are critical for maintaining the activity of both metabolic pathways. In particular, we describe what is now known about the protein–protein interactions between VLCAD and the OXPHOS supercomplex and how their disruption contributes to overall VLCADD pathogenesis. Full article

Newborn screening for very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency in Kuwait was initiated in October 2014. Over a 7-year period (January 2015 to December 2021), 43 newborns were diagnosed with VLCAD deficiency out of 356,819 screened, corresponding to an incidence of 1:8290 and 1:5405 among only Kuwaiti newborns. This study represents the first comprehensive review of newborn screening for VLCAD deficiency in Kuwait. The screening process begins with the detection of elevated blood C14:1 levels in dried blood spots, followed by confirmatory testing using dried blood spots acylcarnitine profiling, with or without molecular testing. Furthermore, this study demonstrates that incorporating the C14:1/C2 ratio as a supplementary marker in first-tier testing alongside C14:1 improves the positive predictive value (PPV) of the current newborn screening for VLCAD deficiency. Adding molecular genetic testing for known VLCAD variants as a second-tier strategy to the national program is also recommended to further enhance specificity and improve PPV. Our findings provide evidence that the expanded newborn screening program in Kuwait has successfully facilitated the early detection of VLCAD deficiency, preventing death and disability in affected infants. Full article

Short-chain acyl-CoA dehydrogenase deficiency (SCADD) is an autosomal recessive inborn error of mitochondrial fatty acid oxidation with highly variable biochemical and genetic characteristics. The present study aimed to estimate the prevalence and genetic characteristics of SCADD in newborns identified through screening. A total of 782,930 newborns were screened for SCADD in Hefei Neonatal Screening Center from January 2016 to December 2023. The blood samples from newborns were measured by tandem mass spectrometry (MS/MS). The suspected SCADD neonates were rechecked using next-generation gene sequencing for diagnosis. Sanger sequencing was used to verify the mutation site for patients with SCADD and their parents. A total of 21 SCADD cases were confirmed, with an incidence rate of 1/37,282. Genetic mutations were identified in all 21 cases, including 15 cases of compound heterozygous variation and 6 cases of homozygous variation. Twenty-one different mutation types and forty-two mutation sites were discovered, with the most frequent mutation being c.1031A>G, accounting for 21.43% (9/42), followed by c.1130C>T, accounting for 16.67% (7/42). Our findings expand the SCADD mutational spectra. c. 1031A>G and c.1130C>T are the common mutation sites for SCADD genes in newborns. SCADD diagnosed through NBS is primarily a benign condition, and early diagnosis is not necessarily essential. Full article

Multiple acyl-CoA dehydrogenase deficiency (MADD) is a rare inborn error of metabolism affecting fatty acid and amino acid oxidation with an incidence of 1 in 200,000 live births. MADD has three clinical phenotypes: severe neonatal-onset with or without congenital anomalies, and a milder late-onset form. Clinical diagnosis is supported by urinary organic acid and blood acylcarnitine analysis using tandem mass spectrometry in newborn screening programs. MADD is an autosomal recessive trait caused by biallelic mutations in the ETFA, ETFB, and ETFDH genes encoding the alpha and beta subunits of the electron transfer flavoprotein (ETF) and ETF-coenzyme Q oxidoreductase enzymes. Despite significant advancements in sequencing techniques, many patients remain undiagnosed, impacting their access to clinical care and genetic counseling. In this report, we achieved a definitive molecular diagnosis in a newborn by combining whole-genome sequencing (WGS) with RNA sequencing (RNA-seq). Whole-exome sequencing and next-generation gene panels fail to detect variants, possibly affecting splicing, in deep intronic regions. Here, we report a unique deep intronic mutation in intron 1 of the ETFDH gene, c.35-959A>G, in a patient with early-onset lethal MADD, resulting in pseudo-exon inclusion. The identified variant is the third mutation reported in this region, highlighting ETFDH intron 1 vulnerability. It cannot be excluded that these intronic sequence features may be more common in other genes than is currently believed. This study highlights the importance of incorporating RNA analysis into genome-wide testing to reveal the functional consequences of intronic mutations. Full article

To date, there have been no review articles specifically relating to the general efficacy and safety of coenzyme Q10 (CoQ10) supplementation in younger subjects. In this article, we therefore reviewed the efficacy and safety of CoQ10 supplementation in neonates (less than 1 month of age), infants (up to 1 year of age) and children (up to 12 years of age). As there is no rationale for the supplementation of CoQ10 in normal younger subjects (as there is in otherwise healthy older subjects), all of the articles in the medical literature reviewed in the present article therefore refer to the supplementation of CoQ10 in younger subjects with a variety of clinical disorders; these include primary CoQ10 deficiency, acyl CoA dehydrogenase deficiency, Duchenne muscular dystrophy, migraine, Down syndrome, ADHD, idiopathic cardiomyopathy and Friedreich’s ataxia. Full article

Very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency is a rare genetic condition affecting the mitochondrial beta-oxidation of long-chain fatty acids. This study reports on the clinical outcomes of patients diagnosed by newborn screening with VLCAD deficiency comparing metabolic parameters, enzyme activities, molecular results, and clinical management. It is a single-center retrospective chart review of VLCAD deficiency patients who met the inclusion criteria between January 2002 and February 2020. The study included 12 patients, 7 of whom had an enzyme activity of more than 10%, and 5 patients had an enzyme activity of less than 10%. The Pearson correlation between enzyme activity and the C14:1 level at newborn screening showed a p-value of 0.0003, and the correlation between enzyme activity and the C14:1 level at diagnosis had a p-value of 0.0295. There was no clear correlation between the number of documented admissions and the enzyme activity level. Patients who had a high C14:1 value at diagnosis were started on a diet with a lower percentage of energy from long-chain triglycerides. The C14:1 result at diagnosis is the value that has been guiding our initial clinical management in asymptomatic diagnosed newborns. However, the newborn screening C14:1 value is the most sensitive predictor of low enzyme activity and may help guide dietary management. Full article

Background: Glutaric aciduria type II (GA II), also known as multiple acyl-CoA dehydrogenase deficiency (MADD), is a rare autosomal recessive metabolic disorder with varied manifestations and onset ages. Case Report: This study presents a distinctive case of a 10-year-old girl who experienced episodic, intermittent vomiting and epigastric pain, particularly aggravated by high-fat and sweet foods. Despite inconclusive physical examinations and routine laboratory tests, and an initial suspicion of cyclic vomiting syndrome, the persistence of recurrent symptoms and metabolic abnormalities (metabolic acidosis and hypoglycemia) during her third hospital admission necessitated further investigation. Advanced diagnostic tests, including urinary organic acid analysis and genetic testing, identified heterozygous pathogenic variants in the ETFDH gene, confirming a diagnosis of GA IIc. The patient showed a positive response to a custom low-protein, low-fat diet supplemented with carnitine and riboflavin. Significance: This case emphasizes the diagnostic challenges associated with recurrent, nonspecific gastrointestinal symptoms in pediatric patients, particularly in differentiating between common gastrointestinal disorders and rare metabolic disorders like GA II. It highlights the importance of considering a broad differential diagnosis to enhance understanding and guide future medical approaches in similar cases. Full article

Very-long-chain acyl-CoA dehydrogenase (VLCAD) deficiency is a long-chain fatty acid oxidation disorder that manifests as either a severe phenotype associated with cardiomyopathy, a hypoglycemic phenotype, or a myopathic phenotype. As the hypoglycemic phenotype can cause sudden infant death, VLCAD deficiency is included in newborn screening (NBS) panels in many countries. The tetradecenoylcarnitine (C14:1) level in dried blood specimens is commonly used as a primary marker for VLCAD deficiency in NBS panels. Its ratio to acetylcarnitine (C2) and various other acylcarnitines is used as secondary markers. In Japan, tandem mass spectrometry-based NBS, initially launched as a pilot study in 1997, was introduced to the nationwide NBS program in 2013. In the present study, we evaluated levels of acylcarnitine with various chain lengths (C18 to C2), free carnitine, and their ratios in 175 infants who tested positive for VLCAD deficiency with C14:1 and C14:1/C2 ratios. Our analyses indicated that the ratios of C14:1 to medium-chain acylcarnitines (C10, C8, and C6) were the most effective markers in reducing false-positive rates. Their use with appropriate cutoffs is expected to improve NBS performance for VLCAD deficiency. Full article