Diagnosis, Treatment and Long-Term Management of Vitamin B12 Deficiency in Adults: A Delphi Expert Consensus.

Background/Objectives: Vitamin B12 deficiency can cause variable symptoms, which may be irreversible if not diagnosed and treated in a timely manner. We aimed to develop a widely accepted expert consensus to guide the practice of diagnosing and treating B12 deficiency. Methods: We conducted a scoping review of the literature published in PubMed since January 2003. Data were used to design a two-round Delphi survey to study the level of consensus among 42 experts. Results: The panelists agreed on the need for educational and organizational changes in the current medical practices for diagnosing and treating B12 deficiency. Recognition of clinical symptoms should receive the highest priority in establishing the diagnosis. There is agreement that the serum B12 concentration is useful as a screening marker and methylmalonic acid or homocysteine can support the diagnosis. Patient lifestyle, disease history, and medications can provide clues to the cause of B12 deficiency. Regardless of the cause of the deficiency, initial treatment with parenteral B12 was regarded as the first choice for patients with acute and severe manifestations of B12 deficiency. The use of high-dose oral B12 at different frequencies may be considered for long-term treatment. Prophylactic B12 supplementation should be considered for specific high-risk groups. Conclusions: There is a consensus that clinical symptoms need to receive more attention in establishing the diagnosis of B12 deficiency. B12 laboratory markers can support the diagnosis. The severity of clinical symptoms, the causes of B12 deficiency, and the treatment goals govern decisions regarding the route and dose of B12 therapy.

A systematic review and meta-analysis of proteomic and metabolomic alterations in anaphylaxis reactions.

Background: Anaphylaxis manifests as a severe immediate-type hypersensitivity reaction initiated through the immunological activation of target B-cells by allergens, leading to the release of mediators. However, the well-known underlying pathological mechanisms do not fully explain the whole variety of clinical and immunological presentations. We performed a systemic review of proteomic and metabolomic studies and analyzed the extracted data to improve our understanding and identify potential new biomarkers of anaphylaxis. Methods: Proteomic and metabolomic studies in both human subjects and experimental models were extracted and selected through a systematic search conducted on databases such as PubMed, Scopus, and Web of Science, up to May 2023. Results: Of 137 retrieved publications, we considered 12 for further analysis, including seven on proteome analysis and five on metabolome analysis. A meta-analysis of the four human studies identified 118 proteins with varying expression levels in at least two studies. Beside established pathways of mast cells and basophil activation, functional analysis of proteomic data revealed a significant enrichment of biological processes related to neutrophil activation and platelet degranulation and metabolic pathways of arachidonic acid and icosatetraenoic acid. The pathway analysis highlighted also the involvement of neutrophil degranulation, and platelet activation. Metabolome analysis across different models showed 13 common metabolites, including arachidonic acid, tryptophan and lysoPC(18:0) lysophosphatidylcholines. Conclusion: Our review highlights the underestimated role of neutrophils and platelets in the pathological mechanisms of anaphylactic reactions. These findings, derived from a limited number of publications, necessitate confirmation through human studies with larger sample sizes and could contribute to the development of new biomarkers for anaphylaxis. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42024506246.

Multiomic analysis in fibroblasts of patients with inborn errors of cobalamin metabolism reveals concordance with clinical and metabolic variability.

BACKGROUND: The high variability in clinical and metabolic presentations of inborn errors of cobalamin (cbl) metabolism (IECM), such as the cblC/epicblC types with combined deficits in methylmalonyl-coA mutase (MUT) and methionine synthase (MS), are not well understood. They could be explained by the impaired expression/activity of enzymes from other metabolic pathways. METHODS: We performed metabolomic, genomic, proteomic, and post-translational modification (PTM) analyses in fibroblasts from three cblC cases and one epi-cblC case compared with three cblG cases with specific MS deficits and control fibroblasts. FINDINGS: CblC patients had metabolic profilings consistent with altered urea cycle, glycine, and energy mitochondrial metabolism. Metabolomic analysis showed partial disruption and increased glutamate/ketoglutarate anaplerotic pathway of the tricarboxylic acid cycle (TCA), in patient fibroblasts. RNA-seq analysis showed decreased expression of MT-TT (mitochondrial tRNA threonine), MT-TP (mitochondrial tRNA proline), OXCT1 (succinyl CoA:3-oxoacid CoA transferase deficiency), and MT-CO1 (cytochrome C oxidase subunit 1). Proteomic changes were observed for key mitochondrial enzymes, including NADH:ubiquinone oxidoreductase subunit A8 (NDUFA8), carnitine palmitoyltransferase 2 (CPT2), and ubiquinol-cytochrome C reductase, complex III subunit X (UQCR10). Propionaldehyde addition in ornithine aminotransferase was the predominant PTM in cblC cells and could be related with the dramatic cellular increase in propionate and methylglyoxalate. It is consistent with the decreased concentration of ornithine reported in 3 cblC cases. Whether the changes detected after multi-omic analyses underlies clinical features in cblC and cblG types of IECM, such as peripheral and central neuropathy, cardiomyopathy, pulmonary hypertension, development delay, remains to be investigated. INTERPRETATION: The omics-related effects of IECM on other enzymes and metabolic pathways are consistent with the diversity and variability of their age-related metabolic and clinical manifestations. PTMs are expected to produce cumulative effects, which could explain the influence of age on neurological manifestations. FUNDING: French Agence Nationale de la Recherche (Projects PREDICTS and EpiGONE) and Inserm.

Towards personalized genome-scale modeling of inborn errors of metabolism for systems medicine applications.

Inborn errors of metabolism (IEMs) are a group of more than 1000 inherited diseases that are individually rare but have a cumulative global prevalence of 50 per 100,000 births. Recently, it has been recognized that like common diseases, patients with rare diseases can greatly vary in the manifestation and severity of symptoms. Here, we review omics-driven approaches that enable an integrated, holistic view of metabolic phenotypes in IEM patients. We focus on applications of Constraint-based Reconstruction and Analysis (COBRA), a widely used mechanistic systems biology approach, to model the effects of inherited diseases. Moreover, we review evidence that the gut microbiome is also altered in rare diseases. Finally, we outline an approach using personalized metabolic models of IEM patients for the prediction of biomarkers and tailored therapeutic or dietary interventions. Such applications could pave the way towards personalized medicine not just for common, but also for rare diseases.

A transgenic mice model of retinopathy of cblG-type inherited disorder of one-carbon metabolism highlights epigenome-wide alterations related to cone photoreceptor cells development and retinal metabolism.

BACKGROUND: MTR gene encodes the cytoplasmic enzyme methionine synthase, which plays a pivotal role in the methionine cycle of one-carbon metabolism. This cycle holds a significant importance in generating S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH), the respective universal methyl donor and end-product of epigenetic transmethylation reactions. cblG type of inherited disorders of vitamin B12 metabolism due to mutations in MTR gene exhibits a wide spectrum of symptoms, including a retinopathy unresponsive to conventional therapies. METHODS: To unveil the underlying epigenetic pathological mechanisms, we conducted a comprehensive study of epigenomic-wide alterations of DNA methylation by NGS of bisulfited retinal DNA in an original murine model with conditional Mtr deletion in retinal tissue. Our focus was on postnatal day 21, a critical developmental juncture for ocular structure refinement and functional maturation. RESULTS: We observed delayed eye opening and impaired visual acuity and alterations in the one-carbon metabolomic profile, with a notable dramatic decline in SAM/SAH ratio predicted to impair DNA methylation. This metabolic disruption led to epigenome-wide changes in genes involved in eye development, synaptic plasticity, and retinoid metabolism, including promoter hypermethylation of Rarα, a regulator of Lrat expression. Consistently, we observed a decline in cone photoreceptor cells and reduced expression of Lrat, Rpe65, and Rdh5, three pivotal genes of eye retinoid metabolism. CONCLUSION: We introduced an original in vivo model for studying cblG retinopathy, which highlighted the pivotal role of altered DNA methylation in eye development, cone differentiation, and retinoid metabolism. This model can be used for preclinical studies of novel therapeutic targets.

Predictors of the utility of clinical exome sequencing as a first-tier genetic test in patients with Mendelian phenotypes: results from a referral center study on 603 consecutive cases.

BACKGROUND: Clinical exome sequencing (CES) provides a comprehensive and effective analysis of relevant disease-associated genes in a cost-effective manner compared to whole exome sequencing. Although several studies have focused on the diagnostic yield of CES, no study has assessed predictors of CES utility among patients with various Mendelian phenotypes. We assessed the effectiveness of CES as a first-level genetic test for molecular diagnosis in patients with a Mendelian phenotype and explored independent predictors of the clinical utility of CES. RESULTS: Between January 2016 and December 2019, 603 patients (426 probands and 177 siblings) underwent CES at the Department of Molecular Medicine of the University Hospital of Nancy. The median age of the probands was 34 years (IQR, 12-48), and the proportion of males was 46.9% (200/426). Adults and children represented 64.8% (276/426) and 35.2% (150/426), respectively. The median test-to-report time was 5.6 months (IQR, 4.1-7.2). CES revealed 203 pathogenic or likely pathogenic variants in 160 patients, corresponding to a diagnostic yield of 37.6% (160/426). Independent predictors of CES utility were criteria strongly suggestive of an extreme phenotype, including pediatric presentation and patient phenotypes associated with an increased risk of a priori probability of a monogenic disorder, the inclusion of at least one family member in addition to the proband, and a CES prescription performed by an expert in the field of rare genetic disorders. CONCLUSIONS: Based on a large dataset of consecutive patients with various Mendelian phenotypes referred for CES as a first-tier genetic test, we report a diagnostic yield of ~ 40% and several independent predictors of CES utility that might improve CES diagnostic efficiency.

Congenital hypothyroidism in children with eutopic gland or thyroid hemiagenesis: prognostic factors for transient vs. permanent hypothyroidism.

OBJECTIVES: More than one third of children with congenital hypothyroidism (CH) and thyroid gland in situ (or eutopic gland) have transient hypothyroidism. It remains difficult to determine early on whether hypothyroidism will be transient which may cause overtreatment and its complications in these children. Our primary aim was to determine prognostic factors for transient hypothyroidism in children with congenital hypothyroidism and eutopic gland or thyroid hemiagenesis. METHODS: We retrospectively reviewed medical records of 111 children, born between 1996 and 2017, diagnosed with congenital hypothyroidism and eutopic gland or hemiagenesis and treated at the Nancy Regional and University Hospital. RESULTS: Fifty four infants (48.6%) had permanent congenital hypothyroidism (PCH) and 57 (51.4%) transient congenital hypothyroidism (TCH). Prognostic factors for TCH included prematurity, twin pregnancy, low birth weight and Apgar score <7, while low FT3 at diagnosis, maternal levothyroxine treatment, a family history of thyroid dysfunction and TSH ≥10 mUI/L while receiving treatment were associated with PCH. Knee epiphyses on X-ray at diagnosis were absent only in children with PCH. The median levothyroxine dose during follow-up was significantly lower in the TCH group compared to the PCH group. A levothyroxine dose of ≤3.95, ≤2.56, ≤2.19 and ≤2.12 µg/kg/day at 6 months, 1, 2 and 3 years of follow-up, respectively, had the best sensitivity-to-specificity ratio for predicting TCH. CONCLUSIONS: Even though it remains difficult to predict the course of hypothyroidism at diagnosis, we were able to identify several prognostic factors for TCH including perinatal problems and lower levothyroxine requirements that can guide the physician on the evolution of hypothyroidism. Clinical Trial Registration Number: NCT04712760.

Hyperhomocysteinemia in Cardiovascular Diseases: Revisiting Observational Studies and Clinical Trials.

Thromboembolic manifestations are relatively frequent in patients with intermediate/severe hyperhomocysteinemia (>30 µmol/L) related to inherited disorders and deficiencies in vitamin B12 and folate. In contrast, moderate hyperhomocysteinemia (15-30 µmol/L) is a modest predictor of cardiovascular risk. The recognition of homocysteine as a cardiovascular risk factor has been challenged by some but not all randomized clinical trials. We reviewed the main data of this controversy and formulated conclusions to be translated in clinical practice.Homocysteine-lowering trials have been performed in cardiovascular subjects with moderate but not intermediate/severe hyperhomocysteinemia despite the dose-effect risk association. The first meta-analyses found no benefit and led cardiology societies not recommending homocysteine in the assessment of cardiovascular risk. This guideline challenged the need to diagnose and treat the nutritional and genetic causes of intermediate/major hyperhomocysteinemia and was not revised when larger meta-analyses concluded to a reduced risk of stroke. In a recent observational study, 84% of consecutive cardiovascular patients assessed for homocysteine had intermediate or major hyperhomocysteinemia, which was properly assessed in only half of the cases and related to B12 and/or folate deficiency and Addison/Biermer disease in 55% of these cases.In conclusion, revisiting observational studies and clinical trials suggests that cardiovascular patients should be screened for hyperhomocysteinemia, when no other risk factor is found. Patients with intermediate/major hyperhomocysteinemia should be properly assessed and treated for B vitamin deficiencies and inherited disorders according to current guidelines. Further trials are needed to assess the effect of lowering homocysteine according to hyperhomocysteinemia categories at baseline.

Vitamin B12 absorption and malabsorption.

Vitamin B12 is assimilated and transported by complex mechanisms that involve three transport proteins, intrinsic factor (IF), haptocorrin (HC) and transcobalamin (TC) and their respective membrane receptors. Vitamin deficiency is mainly due to inadequate dietary intake in vegans, and B12 malabsorption is related to digestive diseases. This review explores the physiology of vitamin B12 absorption and the mechanisms and diseases that produce malabsorption. In the stomach, B12 is released from food carrier proteins and binds to HC. The degradation of HC by pancreatic proteases and the pH change trigger the transfer of B12 to IF in the duodenum. Cubilin and amnionless are the two components of the receptor that mediates the uptake of B12 in the distal ileum. Part of liver B12 is excreted in bile, and undergoes an enterohepatic circulation. The main causes of B12 malabsorption include inherited disorders (Intrinsic factor deficiency, Imerslund-Gräsbeck disease, Addison's pernicious anemia, obesity, bariatric surgery and gastrectomies. Other causes include pancreatic insufficiency, obstructive Jaundice, tropical sprue and celiac disease, bacterial overgrowth, parasitic infestations, Zollinger-Ellison syndrome, inflammatory bowel diseases, chronic radiation enteritis of the distal ileum and short bowel. The assessment of B12 deficit is recommended in the follow-up of subjects with bariatric surgery. The genetic causes of B12 malabsorption are probably underestimated in adult cases with B12 deficit. Despite its high prevalence in the general population and in the elderly, B12 malabsorption cannot be anymore assessed by the Schilling test, pointing out the urgent need for an equivalent reliable test.

Epimutation in inherited metabolic disorders: the influence of aberrant transcription in adjacent genes.

Epigenetic diseases can be produced by a stable alteration, called an epimutation, in DNA methylation, in which epigenome alterations are directly involved in the underlying molecular mechanisms of the disease. This review focuses on the epigenetics of two inherited metabolic diseases, epi-cblC, an inherited metabolic disorder of cobalamin (vitamin B12) metabolism, and alpha-thalassemia type α-ZF, an inherited disorder of α2-globin synthesis, with a particular interest in the role of aberrant antisense transcription of flanking genes in the generation of epimutations in CpG islands of gene promoters. In both disorders, the epimutation is triggered by an aberrant antisense transcription through the promoter, which produces an H3K36me3 histone mark involved in the recruitment of DNA methyltransferases. It results from diverse genetic alterations. In alpha-thalassemia type α-ZF, a deletion removes HBA1 and HBQ1 genes and juxtaposes the antisense LUC7L gene to the HBA2 gene. In epi-cblC, the epimutation in the MMACHC promoter is produced by mutations in the antisense flanking gene PRDX1, which induces a prolonged antisense transcription through the MMACHC promoter. The presence of the epimutation in sperm, its transgenerational inheritance via the mutated PRDX1, and the high expression of PRDX1 in spermatogonia but its nearly undetectable transcription in spermatids and spermatocytes, suggest that the epimutation could be maintained during germline reprogramming and despite removal of aberrant transcription. The epivariation seen in the MMACHC promoter (0.95 × 10-3) is highly frequent compared to epivariations affecting other genes of the Online Catalog of Human Genes and Genetic Disorders in an epigenome-wide dataset of 23,116 individuals. This and the comparison of epigrams of two monozygotic twins suggest that the aberrant transcription could also be influenced by post-zygotic environmental exposures.

Low-frequency Coding Variants Associated With Body Mass Index Affect the Success of Bariatric Surgery.

CONTEXT: A recent study identified 14 low-frequency coding variants associated with body mass index (BMI) in 718 734 individuals predominantly of European ancestry. OBJECTIVE: We investigated the association of 2 genetic scores (GS) with i) the risk of severe/morbid obesity, ii) BMI variation before weight-loss intervention, iii) BMI change in response to an 18-month lifestyle/behavioral intervention program, and iv) BMI change up to 24 months after bariatric surgery. METHODS: The 14 low-frequency coding variants were genotyped or sequenced in 342 French adults with severe/morbid obesity and 574 French adult controls from the general population. We built risk and protective GS based on 6 BMI-increasing and 5 BMI-decreasing low-frequency coding variants that were polymorphic in our study. RESULTS: While the risk GS was not associated with severe/morbid obesity status, BMI-decreasing low-frequency coding variants were significantly less frequent in patients with severe/morbid obesity than in French adults from the general population. Neither the risk nor the protective GS was associated with BMI before intervention in patients with severe/morbid obesity, nor did they affect BMI change in response to a lifestyle/behavioral modification program. The protective GS was associated with a greater BMI decrease following bariatric surgery. The risk and protective GS were associated with a higher and lower risk of BMI regain after bariatric surgery. CONCLUSION: Our data indicate that in populations of European descent, low-frequency coding variants associated with BMI in the general population also affect the outcomes of bariatric surgery in patients with severe/morbid obesity.

Causes and consequences of impaired methionine synthase activity in acquired and inherited disorders of vitamin B12 metabolism.

Methyl-Cobalamin (Cbl) derives from dietary vitamin B12 and acts as a cofactor of methionine synthase (MS) in mammals. MS encoded by MTR catalyzes the remethylation of homocysteine to generate methionine and tetrahydrofolate, which fuel methionine and cytoplasmic folate cycles, respectively. Methionine is the precursor of S-adenosyl methionine (SAM), the universal methyl donor of transmethylation reactions. Impaired MS activity results from inadequate dietary intake or malabsorption of B12 and inborn errors of Cbl metabolism (IECM). The mechanisms at the origin of the high variability of clinical presentation of impaired MS activity are classically considered as the consequence of the disruption of the folate cycle and related synthesis of purines and pyrimidines and the decreased synthesis of endogenous methionine and SAM. For one decade, data on cellular and animal models of B12 deficiency and IECM have highlighted other key pathomechanisms, including altered interactome of MS with methionine synthase reductase, MMACHC, and MMADHC, endoplasmic reticulum stress, altered cell signaling, and genomic/epigenomic dysregulations. Decreased MS activity increases catalytic protein phosphatase 2A (PP2A) and produces imbalanced phosphorylation/methylation of nucleocytoplasmic RNA binding proteins, including ELAVL1/HuR protein, with subsequent nuclear sequestration of mRNAs and dramatic alteration of gene expression, including SIRT1. Decreased SAM and SIRT1 activity induce ER stress through impaired SIRT1-deacetylation of HSF1 and hypomethylation/hyperacetylation of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α), which deactivate nuclear receptors and lead to impaired energy metabolism and neuroplasticity. The reversibility of these pathomechanisms by SIRT1 agonists opens promising perspectives in the treatment of IECM outcomes resistant to conventional supplementation therapies.

Next-generation sequencing and genotype association studies reveal the association of HLA-DRB3*02:02 with delayed hypersensitivity to penicillins.

BACKGROUND: Nonimmediate (delayed)-allergic reactions to penicillins are common and some of them can be life-threatening. The genetic factors influencing these reactions are unknown/poorly known/poorly understood. We assessed the genetic predictors of a delayed penicillin allergy that cover the HLA loci. METHODS: Using next-generation sequencing (NGS), we genotyped the MHC region in 24 patients with delayed hypersensitivity compared with 20 patients with documented immediate hypersensitivity to penicillins recruited in Italy. Subsequently, we analyzed in silico Illumina Immunochip genotyping data that covered the HLA loci in 98 Spanish patients with delayed hypersensitivity and 315 with immediate hypersensitivity compared to 1,308 controls. RESULTS: The two alleles DRB3*02:02:01:02 and DRB3*02:02:01:01 were reported in twenty cases with delayed reactions (83%) and ten cases with immediate reactions (50%), but not in the Allele Frequency Net Database. Bearing at least one of the two alleles increased the risk of delayed reactions compared to immediate reactions, with an OR of 8.88 (95% CI, 3.37-23.32; p < .0001). The haplotype (ACAA) from rs9268835, rs6923504, rs6903608, and rs9268838 genetic variants of the HLA-DRB3 genomic region was significantly associated with an increased risk of delayed hypersensitivity to penicillins (OR, 1.7; 95% CI: 1.06-1.92; p = .001), but not immediate hypersensitivity. CONCLUSION: We showed that the HLA-DRB3 locus is strongly associated with an increased risk of delayed penicillin hypersensitivity, at least in Southwestern Europe. The determination of HLA-DRB3*02:02 alleles in the risk management of severe delayed hypersensitivity to penicillins should be evaluated further in larger population samples of different origins.

Ocular manifestations in patients with inborn errors of intracellular cobalamin metabolism: a systematic review.

Inherited disorders of cobalamin (cbl) metabolism (cblA-J) result in accumulation of methylmalonic acid (MMA) and/or homocystinuria (HCU). Clinical presentation includes ophthalmological manifestations related to retina, optic nerve and posterior visual alterations, mainly reported in cblC and sporadically in other cbl inborn errors.We searched MEDLINE EMBASE and Cochrane Library, and analyzed articles reporting ocular manifestations in cbl inborn errors. Out of 166 studies a total of 52 studies reporting 163 cbl and 24 mut cases were included. Ocular manifestations were found in all cbl defects except for cblB and cblD-MMA; cblC was the most frequent disorder affecting 137 (84.0%) patients. The c.271dupA was the most common pathogenic variant, accounting for 70/105 (66.7%) cases. One hundred and thirty-seven out of 154 (88.9%) patients presented with early-onset disease (0-12 months). Nystagmus and strabismus were observed in all groups with the exception of MMA patients while maculopathy and peripheral retinal degeneration were almost exclusively found in MMA-HCU patients. Optic nerve damage ranging from mild temporal disc pallor to complete atrophy was prevalent in MMA-HCU.and MMA groups. Nystagmus was frequent in early-onset patients. Retinal and macular degeneration worsened despite early treatment and stabilized systemic function in these patients. The functional prognosis remains poor with final visual acuity < 20/200 in 55.6% (25/45) of cases. In conclusion, the spectrum of eye disease in Cbl patients depends on metabolic severity and age of onset. The development of visual manifestations over time despite early metabolic treatment point out the need for specific innovative therapies.

Hypozincemia in the early stage of COVID-19 is associated with an increased risk of severe COVID-19.

BACKGROUND & AIMS: Nutritional predisposition to severe coronavirus disease 2019 (COVID-19) remains unclear. Zinc deficiency could be critical since it is associated with a higher susceptibility to infections. We evaluated the prevalence of hypozincemia in the early stage of COVID-19, its association with risk factors for severe COVID-19 and its prognostic value for hospitalization for respiratory complications within 10 days. METHODS: For 152 COVID-19 patients and 88 non-COVID-19 patients admitted to COVID-19 screening centers, national early warning score for COVID-19 (NEWS) and laboratory analyses were performed to identify the risk for severe COVID-19. Multivariable logistic regression analysis assessed whether hypozincemia was an independent predictor of hospitalization for respiratory complications within 10 days (primary judgment criterion). The secondary judgment criteria were high NEWS score (≥7), comorbidities and biomarkers associated with severe COVID-19. RESULTS: Hypozincemia was more frequent in COVID-19 patients compared to non-COVID-19 patients (27.6% vs 11.4%; p = 0.003). Older patients (≥65 years) and medically assisted nursing home residents were at higher risk of hypozincemia (p < 0.01). Hypozincemia was associated with a worse NEWS score (p < 0.01) and lymphopenia (p < 0.001). Hypozincemia was independently associated with hospitalization for respiratory complications within 10 days (OR = 10.9, 95% CI = 2.3-51.6, p = 0.002). CONCLUSIONS: In the early stage of COVID-19, the prevalence of hypozincemia exceeded 20%. Hypozincemia was an independent predictor of hospitalization for respiratory complications within 10 days. This may suggest the importance of early detection and treatment of zinc deficiency in the nutritional management of COVID-19, especially in older people. Therefore, intervention and adjuvant treatment trials are strongly needed.

Programming by Methyl Donor Deficiency during Pregnancy and Lactation Produces Cardiomyopathy in Adult Rats Subjected to High Fat Diet.

SCOPE: Vitamin B12 and folate (methyl donors) deficiency is frequent during pregnancy. Experimental rat models with methyl donor deficit during pregnancy and lactation (Initial methyl donor deficit (iMDD)) produce impaired myocardium fatty acid oxidation and mitochondrial energy metabolism at weaning. METHODS AND RESULTS: The consequences of iMDD on heart of rat pups under normal diet after weaning and high fat diet (HF) between day (D) 50 and D185 are investigated. iMDD/HF induces increased histological fibrosis and increased B-type natriuretic peptide blood level. Inflammation is evidenced by increased protein expression of NFkB, Caspase1, and IL1ß and fibrosis by increased expression of αSMA, col1a1, and col1a2 in females, but not in males. Fibrosis is related to increased angiotensin at D50 and D185 and increased protein expression of TGFB1 and AT1 angiotensin receptors at D185. The limited fibrosis in males is consistent with increased expression of AT2, the antagonist receptor of AT1. The increased expression of GLUT4 and decreased expression of PGC1α and PPARα reflect a shift from fatty acid oxidation to glycolysis. CONCLUSION: Developmental programming by iMDD produces cardiomyopathy in female offspring exposed to HF. The cardiomyopathy is linked to inflammation and fibrosis through angiotensin-AT2 and TGFB1 pathways and alteration of energy metabolism.

[Newborn screening of phenylketonuria in France]. / Le dépistage de la phénylcétonurie en France.

Phenylketonuria is the most common inborn error of metabolism and causes irreversible mental retardation if left untreated. Its newborn screening was made possible by the technique of blood collection on filter paper developed by Robert Guthrie. Neonatal PKU screening began in France in the early 1970s. It was initially carried out by a bacteriological method, then by fluorometry, and finally, since 2020, by tandem mass spectrometry. More than 35 million newborns have been screened to date. This resulted in the diagnosis of more than 3,500 children with PKU or mild hyperphenylalaninemia. The management of these children has improved over time, in particular thanks to the techniques of biochemistry and molecular genetics which lead to an accurate diagnosis and the arrival of drug treatment by sapropterin. Thanks to this screening, which allows for early management, the prognosis of PKU has been transformed and, although neurological or behavioral problems may arise, these patients are living normally today.

TITLE: Le dépistage de la phénylcétonurie en France. ABSTRACT: La phénylcétonurie (PCU) est la plus fréquente des erreurs innées du métabolisme et entraîne un retard mental irréversible en l'absence de traitement. Son dépistage néonatal a été rendu possible grâce à la technique de recueil de sang sur papier buvard mise au point par Robert Guthrie. Le dépistage néonatal de la PCU a débuté en France au début des années 1970. Il a été initialement réalisé par une technique bactériologique, puis fluorimétrique et, enfin, depuis 2020 par spectrométrie de masse en tandem. Plus de 35 millions de nouveau-nés ont été dépistés à ce jour, ce qui a permis de diagnostiquer plus de 3 500 enfants porteurs de PCU ou hyperphénylalaninémie modérée. La prise en charge de ces enfants a évolué avec le temps, en particulier grâce aux techniques de biochimie et de génétique moléculaire qui permettent un diagnostic précis et grâce à l'arrivée d'un traitement médicamenteux par saproptérine. Grâce à ce dépistage, qui permet une prise en charge précoce, le pronostic de la PCU a été transformé et, même s'il peut survenir des problèmes neurologiques ou comportementaux, ces patients ont une vie normale aujourd'hui.

Fetal Programming by Methyl Donor Deficiency Produces Pathological Remodeling of the Ascending Aorta.

[Figure: see text].