Acidémie isovalérique (caractérisation génétique et étude du métabolisme de la leucine dans les fibroblastes)

LYON1-BU Santé (693882101) / SudocSudocFranceF

Bone Disease in Nephropathic Cystinosis: Beyond Renal Osteodystrophy

International audiencePatients with chronic kidney disease (CKD) display significant mineral and bone disorders (CKD-MBD) that induce significant cardiovascular, growth and bone comorbidities. Nephropathic cystinosis is an inherited metabolic disorder caused by the lysosomal accumulation of cystine due to mutations in the CTNS gene encoding cystinosin, and leads to end-stage renal disease within the second decade. The cornerstone of management relies on cysteamine therapy to decrease lysosomal cystine accumulation in target organs. However, despite cysteamine therapy, patients display severe bone symptoms, and the concept of "cystinosis metabolic bone disease" is currently emerging. Even though its exact pathophysiology remains unclear, at least five distinct but complementary entities can explain bone impairment in addition to CKD-MBD: long-term consequences of renal Fanconi syndrome, malnutrition and copper deficiency, hormonal disturbances, myopathy, and intrinsic/iatrogenic bone defects. Direct effects of both CTNS mutation and cysteamine on osteoblasts and osteoclasts are described. Thus, the main objective of this manuscript is not only to provide a clinical update on bone disease in cystinosis, but also to summarize the current experimental evidence demonstrating a functional impairment of bone cells in this disease and to discuss new working hypotheses that deserve future research in the field

Monitoring of asparagine depletion and anti-L-asparaginase antibodies in adult acute lymphoblastic leukemia treated in the pediatric-inspired GRAALL-2005 trial

International audienceno abstrac

Angelman syndrome and isovaleric acidemia: What is the link?

We report a toddler affected with Angelman syndrome and isovaleric acidemia (IVA). Such association was due to paternal uniparental isodisomy (UPD) of chromosome 15 in which the proband inherited two paternal copies of an IVA gene point mutation. As both diseases may have severe impact on neurodevelopment, adequate treatment of IVA should be discussed. In our patient however, the variant identified likely causes asymptomatic organic aciduria. Such findings emphasize that paternal UPD 15 can rarely lead to co-occurrence of Angelman syndrome and potentially treatable inborn errors of metabolism

Plasma acetyl- l -carnitine and l -carnitine in major depressive episodes: a case–control study before and after treatment

Abstract Background Major depressive disorder (MDD) is the main cause of disability worldwide, its outcome is poor, and its underlying mechanisms deserve a better understanding. Recently, peripheral acetyl- l -carnitine (ALC) has been shown to be lower in patients with major depressive episodes (MDEs) than in controls. l -Carnitine is involved in mitochondrial function and ALC is its short-chain acetyl-ester. Our first aim was to compare the plasma levels of l -carnitine and ALC, and the l -carnitine/ALC ratio in patients with a current MDE and healthy controls (HCs). Our second aim was to assess their changes after antidepressant treatment. Methods l -Carnitine and ALC levels and the carnitine/ALC ratio were measured in 460 patients with an MDE in a context of MDD and in 893 HCs. Depressed patients were re-assessed after 3 and 6 months of antidepressant treatment for biology and clinical outcome. Results As compared to HC, depressed patients had lower ALC levels ( p < 0.00001), higher l -carnitine levels ( p < 0.00001) and higher l -carnitine/ALC ratios ( p < 0.00001). ALC levels increased [coefficient: 0.18; 95% confidence interval (CI) 0.12–0.24; p < 0.00001], and l -carnitine levels (coefficient: −0.58; 95% CI −0.75 to −0.41; p < 0.00001) and l -carnitine/ALC ratios (coefficient: −0.41; 95% CI −0.47 to −0.34; p < 0.00001), decreased after treatment. These parameters were completely restored after 6 months of antidepressant. Moreover, the baseline l -carnitine/ALC ratio predicted remission after 3 months of treatment (odds ratio = 1.14; 95% CI 1.03–1.27; p = 0.015). Conclusions Our data suggest a decreased mitochondrial metabolism of l -carnitine into ALC during MDE. This decreased mitochondrial metabolism is restored after a 6-month antidepressant treatment. Moreover, the magnitude of mitochondrial dysfunction may predict remission after 3 months of antidepressant treatment. New strategies targeting mitochondria should be explored to improve treatments of MDD

Collaboration between academics, small pharmaceutical company and patient organizations in the development of a new formulation of cysteamine in nephropathic cystinosis: A successful story

International audienceRare diseases usually concern small and disseminated population. Implementing clinical research with the right design, outcomes measures and the recruitment of patients are challenges. Collaborations, training and multidisciplinary approach are often required. In this article, we provide an overview of a successful collaboration in nephropathic cystinosis (NC), focusing on what was the key of success, the interactions between academics, the pharmaceutical company and patients organizations. NC is considered as a very rare disease. In 2010, a new formulation of cysteamine, the only available treatment to improve renal outcome of the disease, was proposed by a small American company. Studies were implemented in France under the coordination of an expert of the disease and the clinical investigation center of Lyon. The collaboration resulted in a good recruitment and retention of the patients in the study and most of all in the availability of the new formulation in France. Patients could have facilitated the research by being involved in the early stages of the studies. Involving patients and public early in the process is particularly important in rare diseases as the patient is a great source of knowledge and has his own expectations. Priorities of research, design, conduct and reporting of clinical trials can be defined in collaboration with adults but also with young patients or public, the first concerned in rare diseases. This concept is still to be developed and improved especially with paediatric patients

Newborn Screening of Primary Carnitine Deficiency: An Overview of Worldwide Practices and Pitfalls to Define an Algorithm before Expansion of Newborn Screening in France

Primary Carnitine Deficiency (PCD) is a fatty acid oxidation disorder that will be included in the expansion of the French newborn screening (NBS) program at the beginning of 2023. This disease is of high complexity to screen, due to its pathophysiology and wide clinical spectrum. To date, few countries screen newborns for PCD and struggle with high false positive rates. Some have even removed PCD from their screening programs. To understand the risks and pitfalls of implementing PCD to the newborn screening program, we reviewed and analyzed the literature to identify hurdles and benefits from the experiences of countries already screening this inborn error of metabolism. In this study, we therefore, present the main pitfalls encountered and a worldwide overview of current practices in PCD newborn screening. In addition, we address the optimized screening algorithm that has been determined in France for the implementation of this new condition

Metabolomic profiles of 38 acylcarnitines in major depressive episodes before and after treatment

Abstract Background Major depression is associated with changes in plasma L-carnitine and acetyl-L-carnitine. But its association with acylcarnitines remains unclear. The aim of this study was to assess metabolomic profiles of 38 acylcarnitines in patients with major depression before and after treatment compared to healthy controls (HCs). Methods Metabolomic profiles of 38 plasma short-, medium-, and long-chain acylcarnitines were performed by liquid chromatography-mass spectrometry in 893 HCs from the VARIETE cohort and 460 depressed patients from the METADAP cohort before and after 6 months of antidepressant treatment. Results As compared to HCs, depressed patients had lower levels of medium- and long-chain acylcarnitines. After 6 months of treatment, increased levels of medium- and long-chain acyl-carnitines were observed that no longer differed from those of controls. Accordingly, several medium- and long-chain acylcarnitines were negatively correlated with depression severity. Conclusions These medium- and long-chain acylcarnitine dysregulations argue for mitochondrial dysfunction through fatty acid β -oxidation impairment during major depression

Mutations in KARS cause a severe neurological and neurosensory disease with optic neuropathy

Mutations in genes encoding aminoacyl‐tRNA synthetases have been reported in several neurological disorders. KARS is a dual localized lysyl‐tRNA synthetase and its cytosolic isoform belongs to the multiple aminoacyl‐tRNA synthetase complex (MSC). Biallelic mutations in the KARS gene were described in a wide phenotypic spectrum ranging from nonsyndromic deafness to complex impairments. Here, we report on a patient with severe neurological and neurosensory disease investigated by whole‐exome sequencing and found to carry biallelic mutations c.683C>T (p.Pro228Leu) and c.871T>G (p.Phe291Val), the second one being novel, in the KARS gene. The patient presented with an atypical clinical presentation with an optic neuropathy not previously reported. At the cellular level, we show that cytoplasmic KARS was expressed at a lower level in patient cells and displayed decreased interaction with MSC. In vitro, these two KARS variants have a decreased aminoacylation activity compared with wild‐type KARS, the p.Pro228Leu being the most affected. Our data suggest that dysfunction of cytoplasmic KARS resulted in a decreased level of translation of the nuclear‐encoded lysine‐rich proteins belonging to the respiratory chain complex, thus impairing mitochondria functions