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Molecular Genetics and Metabolism Jun 2024Glutaric aciduria type II (GAII) is a heterogeneous genetic disorder affecting mitochondrial fatty acid, amino acid and choline oxidation. Clinical manifestations vary...
Glutaric aciduria type II (GAII) is a heterogeneous genetic disorder affecting mitochondrial fatty acid, amino acid and choline oxidation. Clinical manifestations vary across the lifespan and onset may occur at any time from the early neonatal period to advanced adulthood. Historically, some patients, in particular those with late onset disease, have experienced significant benefit from riboflavin supplementation. GAII has been considered an autosomal recessive condition caused by pathogenic variants in the gene encoding electron-transfer flavoprotein ubiquinone-oxidoreductase (ETFDH) or in the genes encoding electron-transfer flavoprotein subunits A and B (ETFA and ETFB respectively). Variants in genes involved in riboflavin metabolism have also been reported. However, in some patients, molecular analysis has failed to reveal diagnostic molecular results. In this study, we report the outcome of molecular analysis in 28 Australian patients across the lifespan, 10 paediatric and 18 adult, who had a diagnosis of glutaric aciduria type II based on both clinical and biochemical parameters. Whole genome sequencing was performed on 26 of the patients and two neonatal onset patients had targeted sequencing of candidate genes. The two patients who had targeted sequencing had biallelic pathogenic variants (in ETFA and ETFDH). None of the 26 patients whose whole genome was sequenced had biallelic variants in any of the primary candidate genes. Interestingly, nine of these patients (34.6%) had a monoallelic pathogenic or likely pathogenic variant in a single primary candidate gene and one patient (3.9%) had a monoallelic pathogenic or likely pathogenic variant in two separate genes within the same pathway. The frequencies of the damaging variants within ETFDH and FAD transporter gene SLC25A32 were significantly higher than expected when compared to the corresponding allele frequencies in the general population. The remaining 16 patients (61.5%) had no pathogenic or likely pathogenic variants in the candidate genes. Ten (56%) of the 18 adult patients were taking the selective serotonin reuptake inhibitor antidepressant sertraline, which has been shown to produce a GAII phenotype, and another two adults (11%) were taking a serotonin-norepinephrine reuptake inhibitor antidepressant, venlafaxine or duloxetine, which have a mechanism of action overlapping that of sertraline. Riboflavin deficiency can also mimic both the clinical and biochemical phenotype of GAII. Several patients on these antidepressants showed an initial response to riboflavin but then that response waned. These results suggest that the GAII phenotype can result from a complex interaction between monoallelic variants and the cellular environment. Whole genome or targeted gene panel analysis may not provide a clear molecular diagnosis.
PubMed: 38941880
DOI: 10.1016/j.ymgme.2024.108516 -
Nutrients Jun 2024Depression is a major global health concern expected to worsen by 2030. In 2019, 28 million individuals were affected by depressive disorders. Dietary and supplemental... (Review)
Review
Depression is a major global health concern expected to worsen by 2030. In 2019, 28 million individuals were affected by depressive disorders. Dietary and supplemental vitamins show overall favorable preventative and therapeutic effects on depression. B vitamins are crucial for neurological function and mood regulation. Deficiencies in these vitamins are linked to depression. Studies on individual B vitamins show promise in improving depressive symptoms, particularly thiamin, riboflavin, niacin, and folate. Vitamin C deficiency may heighten depressive symptoms, but its exact role is not fully understood. Seasonal Affective Disorder (SAD) is associated with insufficient sunlight exposure and vitamin D deficiency. Vitamin D supplementation for SAD shows inconsistent results due to methodological variations. Further investigation is needed to understand the mechanisms of vitamins in depression treatment. Moreover, more research on SAD and light therapy's efficacy and underlying mechanisms involving photoreceptors, enzymes, and immune markers is needed. Although dietary and supplemental vitamins show overall favorable preventative and therapeutic effects on depression, dietitians treating psychiatric disorders face challenges due to diverse study designs, making direct comparisons difficult. Therefore, this article reviews the current literature to assess the role of dietary and supplemental vitamins in the prevention and treatment of depression. This review found that, although evidence supports the role of B vitamins and vitamins C and D in preventing and treating depression, further research is needed to clarify their mechanisms of action and determine the most effective intervention strategies.
Topics: Humans; Seasonal Affective Disorder; Vitamin D; Dietary Supplements; Vitamins; Depression; Adult; Ascorbic Acid; Vitamin B Complex; Vitamin D Deficiency; Female; Solubility
PubMed: 38931257
DOI: 10.3390/nu16121902 -
Journal of Clinical Medicine May 2024Progressive auditory dysfunction is common in patients with generalized neurodegenerative conditions, but clinicians currently lack the diagnostic tools to determine the...
BACKGROUND
Progressive auditory dysfunction is common in patients with generalized neurodegenerative conditions, but clinicians currently lack the diagnostic tools to determine the location/degree of the pathology and, hence, to provide appropriate intervention. In this study, we present the white-matter microstructure measurements derived from a novel diffusion-weighted magnetic resonance imaging (dMRI) technique in a patient with axonal auditory neuropathy and consider the findings in relation to the auditory intervention outcomes.
METHODS
We tracked the hearing changes in an adolescent with Riboflavin Transporter Deficiency (Type 2), evaluating the sound detection/discrimination, auditory evoked potentials, and both structural- and diffusion-weighted MRI findings over a 3-year period. In addition, we explored the effect of bilateral cochlear implantation in this individual.
RESULTS
Between the ages of 15 years and 18 years, the patient showed a complete loss of functional hearing ability. The auditory brainstem response testing indicated an auditory neuropathy with evidence of normal cochlear function but disrupted auditory neural activity. While three structural MRI assessments across this period showed a clinically normal cochleovestibular anatomy, the dMRI evaluation revealed a significant loss of fiber density consistent with axonopathy. The subsequent cochlear implant function was affected with the high levels of current required to elicit auditory sensations and concomitant vestibular and facial nerve stimulation issues.
CONCLUSIONS
The case study demonstrates the ability of dMRI technologies to identify the subtle white-matter microstructure changes in the auditory pathway, which may disrupt the neural function in patients with auditory axonopathy.
PubMed: 38892782
DOI: 10.3390/jcm13113072 -
Mitochondrion May 2024Pathogenic ACAD9 variants cause complex I deficiency. Patients presenting in infancy unresponsive to riboflavin have high mortality. A six-month-old infant presented...
Pathogenic ACAD9 variants cause complex I deficiency. Patients presenting in infancy unresponsive to riboflavin have high mortality. A six-month-old infant presented with riboflavin unresponsive lactic acidosis and life-threatening cardiomyopathy. Treatment with high dose bezafibrate and nicotinamide riboside resulted in marked clinical improvement including reduced lactate and NT-pro-brain type natriuretic peptide levels, with stabilized echocardiographic measures. After a long stable period, the child succumbed from cardiac failure with infection at 10.5 months. Therapy was well tolerated. Peak bezafibrate levels exceeded its EC. The clinical improvement with this treatment illustrates its potential, but weak PPAR agonist activity of bezafibrate limited its efficacy.
PubMed: 38797357
DOI: 10.1016/j.mito.2024.101905 -
Food Chemistry Sep 2024B-group vitamins are important micronutrients for maintaining human health; nevertheless, B vitamin deficiency is a globally widespread issue. Thus, it is relevant to...
B-group vitamins are important micronutrients for maintaining human health; nevertheless, B vitamin deficiency is a globally widespread issue. Thus, it is relevant to accurately assess the B-vitamin content in staple crop products such as wheat grains. Here, we developed a multi-enzyme extraction method allowing accurate quantification of seven B vitamins in wheat using ultra high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Free forms of thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7) and folates (B9) were determined with recoveries ranging from 81 to 118% and accuracy below 15% bias. The precision was below 20% relative standard deviation and the internal standards adequately compensated for matrix effects. The method was applied to determine the B vitamin stabilities in wheat grains stored at different temperatures and periods. The results provide an important basis in future studies aiming at understanding nutritional availability of B vitamins.
Topics: Triticum; Tandem Mass Spectrometry; Chromatography, High Pressure Liquid; Vitamin B Complex
PubMed: 38776794
DOI: 10.1016/j.foodchem.2024.139667 -
Frontiers in Pediatrics 2024Brown-Vialetto-Van Laere (BVVL) syndrome is an extremely rare autosomal recessive progressive motoneuron disease that is caused by a defect in the riboflavin transporter...
BACKGROUND
Brown-Vialetto-Van Laere (BVVL) syndrome is an extremely rare autosomal recessive progressive motoneuron disease that is caused by a defect in the riboflavin transporter genes SLC52A2 and SLC52A3. BVVL syndrome has a variable age of presentation, and it is characterized by progressive auditory neuropathy, bulbar palsy, stridor, muscle weakness, and respiratory compromise secondary to diaphragmatic and vocal cord paralysis. BVVL syndrome has a poor prognosis in the absence of treatment, including morbidity with quadriparesis and sensorineural hearing loss, with mortality in the younger age group. Early administration of riboflavin is associated with prolonged survival, low morbidity, and reversal of some clinical manifestations.
CASE PRESENTATION
We describe an 18-month-old male infant with progressive pontobulbar palsy, loss of developmental milestones, and a clinical picture suggestive of chronic inflammatory demyelinating neuropathy. A nerve conduction study revealed axonal neuropathy, while molecular analysis revealed a homozygous mutation in one of the riboflavin transporter genes, SLC52A3, confirming BVVL syndrome. The patient needed long-term respiratory support and a gastrostomy tube to support feeding. With high-dose riboflavin supplementation, he experienced moderate recovery of motor function.
CONCLUSION
This report highlights the importance of considering BVVL syndrome in any patient who presents with the clinical phenotype of pontobulbar palsy and peripheral axonal neuropathy, as early riboflavin treatment may improve or halt disease progression, thus reducing the associated mortality and morbidity.
PubMed: 38745833
DOI: 10.3389/fped.2024.1377515 -
Nutrition Reviews May 2024Riboflavin (vitamin B2) is a water-soluble micronutrient considered to be a precursor of the nucleotides flavin adenine dinucleotide and flavin mononucleotide. This...
CONTEXT
Riboflavin (vitamin B2) is a water-soluble micronutrient considered to be a precursor of the nucleotides flavin adenine dinucleotide and flavin mononucleotide. This vitamin makes up mitochondrial complexes and participates as an enzymatic cofactor in several mechanisms associated with energy metabolism.
OBJECTIVE
This systematic review collected and discussed the most relevant results on the role of riboflavin in the energy metabolism of lipids, proteins, and carbohydrates.
DATA SOURCES
A systematic search was carried out in the PubMed-Medline, Scopus, Embase, and Web of Science databases using the PICOS (Population, Intervention, Comparison, Outcome, Study design) strategy.
DATA EXTRACTION
The screening of studies went through 2 stages following predefined eligibility criteria. The information extracted covered reference details, study design, population characteristics, experimental model, treatment parameters and dosage, route of administration, duration of treatment, and results found.
DATA ANALYSIS
The risk of bias was assessed using the SYRCLE Risk of Bias (RoB) tool for in vivo studies and the QUIN tool adapted for in vitro studies, utilizing 10 domains, including selection bias, performance bias, detection bias, attrition bias, reporting bias, and other biases, to evaluate the methodological quality of the included studies.
CONCLUSION
This review concludes that riboflavin regulates energy metabolism by activating primary metabolic pathways and is involved in energy balance homeostasis.
PubMed: 38719205
DOI: 10.1093/nutrit/nuae041 -
Revue Neurologique May 2024Distal hereditary motor neuropathies (dHMN) are a group of heterogeneous hereditary disorders characterized by a slowly progressive distal pure motor neuropathy.... (Review)
Review
Distal hereditary motor neuropathies (dHMN) are a group of heterogeneous hereditary disorders characterized by a slowly progressive distal pure motor neuropathy. Electrophysiology, with normal motor and sensory conduction velocities, can suggest the diagnosis of dHMN and guide the genetic study. More than thirty genes are currently associated with HMNs, but around 60 to 70% of cases of dHMN remain uncharacterized genetically. Recent cohort studies showed that HSPB1, GARS, BICB2 and DNAJB2 are among the most frequent dHMN genes and that the prevalence of the disease was calculated as 2.14 and 2.3 per 100,000. The determination of the different genes involved in dHMNs made it possible to observe a genotypic overlap with some other neurogenetic disorders and other hereditary neuropathies such as CMT2, mainly with the HSPB1, HSPB8, BICD2 and TRPV4 genes of AD-inherited transmission and recently observed with SORD gene of AR transmission which seems relatively frequent and potentially curable. Distal hereditary motor neuropathy that predominates in the upper limbs is linked mainly to three genes: GARS, BSCL2 and REEP1, whereas dHMN with vocal cord palsy is associated with SLC5A7, DCTN1 and TRPV4 genes. Among the rare AR forms of dHMN like IGHMBP2 and DNAJB2, the SIGMAR1 gene mutations as well as VRK1 variants are associated with a motor neuropathy phenotype often associated with upper motoneuron involvement. The differential diagnosis of these latter arises with juvenile forms of amyotrophic lateral sclerosis, that could be caused also by variations of these genes, as well as hereditary spastic paraplegia. A differential diagnosis of dHMN related to Brown Vialetto Van Laere syndrome due to riboflavin transporter deficiency is important to consider because of the therapeutic possibility.
PubMed: 38702287
DOI: 10.1016/j.neurol.2023.09.005 -
Frontiers in Pediatrics 2024Riboflavin transporter deficiency (RTD) is a rare genetic disorder that affects riboflavin transport, leading to impaired red blood cell production and resulting in pure...
INTRODUCTION
Riboflavin transporter deficiency (RTD) is a rare genetic disorder that affects riboflavin transport, leading to impaired red blood cell production and resulting in pure red cell aplasia. Recognizing and understanding its clinical manifestations, diagnosis, and management is important.
CASE PRESENTATION
A 2-year-old patient presented with pure red cell aplasia as the primary symptom of RTD. After confirming the diagnosis, rapid reversal of anemia was achieved after high-dose riboflavin treatment.
CONCLUSION
RTD often has an insidious onset, and neurological symptoms appear gradually as the disease progresses, making it prone to misdiagnosis. Genetic testing and bone marrow biopsy can confirm the diagnosis.
PubMed: 38694724
DOI: 10.3389/fped.2024.1391245 -
The ISME Journal Jan 2024The endosymbiosis between the pathogenic fungus Rhizopus microsporus and the toxin-producing bacterium Mycetohabitans rhizoxinica represents a unique example of host...
The endosymbiosis between the pathogenic fungus Rhizopus microsporus and the toxin-producing bacterium Mycetohabitans rhizoxinica represents a unique example of host control by an endosymbiont. Fungal sporulation strictly depends on the presence of endosymbionts as well as bacterially produced secondary metabolites. However, an influence of primary metabolites on host control remained unexplored. Recently, we discovered that M. rhizoxinica produces FO and 3PG-F420, a derivative of the specialized redox cofactor F420. Whether FO/3PG-F420 plays a role in the symbiosis has yet to be investigated. Here, we report that FO, the precursor of 3PG-F420, is essential to the establishment of a stable symbiosis. Bioinformatic analysis revealed that the genetic inventory to produce cofactor 3PG-F420 is conserved in the genomes of eight endofungal Mycetohabitans strains. By developing a CRISPR/Cas-assisted base editing strategy for M. rhizoxinica, we generated mutant strains deficient in 3PG-F420 (M. rhizoxinica ΔcofC) and in both FO and 3PG-F420 (M. rhizoxinica ΔfbiC). Co-culture experiments demonstrated that the sporulating phenotype of apo-symbiotic R. microsporus is maintained upon reinfection with wild-type M. rhizoxinica or M. rhizoxinica ΔcofC. In contrast, R. microsporus is unable to sporulate when co-cultivated with M. rhizoxinica ΔfbiC, even though the fungus was observed by super-resolution fluorescence microscopy to be successfully colonized. Genetic and chemical complementation of the FO deficiency of M. rhizoxinica ΔfbiC led to restoration of fungal sporulation, signifying that FO is indispensable for establishing a functional symbiosis. Even though FO is known for its light-harvesting properties, our data illustrate an important role of FO in inter-kingdom communication.
Topics: Symbiosis; Rhizopus; Spores, Fungal; Flavins; CRISPR-Cas Systems; Riboflavin
PubMed: 38691425
DOI: 10.1093/ismejo/wrae074