bims-curels Biomed News
on Leigh syndrome
Issue of 2023‒09‒10
ten papers selected by
Cure Mito Foundation

  1. Orphanet J Rare Dis. 2023 Sep 04. 18(1): 264
      BACKGROUND: Leigh Syndrome (LS) is a rare genetic neurometabolic disorder, that leads to the degeneration of the central nervous system and subsequently, early death. LS can be caused by over 80 mutations in mitochondrial or nuclear DNA. Patient registries are important for many reasons, such as studying the natural history of the disease, improving the quality of care, and understanding the healthcare burden. For rare diseases, patient registries are significantly important as patient numbers are small, and funding is limited. Cure Mito Foundation started a global patient registry for LS in September 2021 to identify and learn about the LS patient population, facilitate clinical trial recruitment, and unite international patients and researchers. Priorities were to allow researchers and industry partners to access data at no cost through a clear and transparent process, active patient engagement, and sharing of results back to the community.RESULTS: Patient registry platform, survey design, data analysis process, and patient recruitment strategies are described. Reported results include demographics, diagnostic information, symptom history, loss of milestones, disease management, healthcare utilization, quality of life, and caregiver burden for 116 participants. Results show a high disease burden, but a relatively short time to diagnosis. Despite the challenges faced by families impacted by Leigh syndrome, participants, in general, are described as having a good quality of life and caregivers are overall resilient, while also reporting a significant amount of stress.
    CONCLUSION: This registry provides a straightforward, no-cost mechanism for data sharing and contacting patients for clinical trials or research participation, which is important given the recruitment challenges for clinical trials for rare diseases. This is the first publication to present results from a global patient registry for Leigh Syndrome, with details on a variety of patient-specific and caregiver outcomes reported for the first time. Additionally, this registry is the first for any mitochondrial disease with nearly 70% of participants residing outside of the United States. Future efforts include continued publication of results and further collaboration with patients, industry partners, and researchers.
    Keywords:  Clinical trials; Hope; Leigh disease; Leigh syndrome; Mitochondrial disease; Patient driven; Patient registry; Rare disease; Real world data; Research
  2. Res Involv Engagem. 2023 Sep 08. 9(1): 78
      BACKGROUND: The CHILD-BRIGHT Network created a parent peer mentor (PPM) role to support other parents who were engaging as partners in the different research projects and activities of the network. We aim to describe how a PPM functioned to support parent-partners of children with disabilities in research projects within the Network.METHODS: In this case study, the PPM approached 50 parent-partners and scheduled a 1-on-1 initial telephone call to offer support for any issues arising. When consent was provided, the PPM recorded interactions with network parent-partners in a communication report in an Excel form. Also, verbatim transcription from one in-depth interview with the PPM was included for data analysis using qualitative description. The Guidance for Reporting Involvement of Patients and the Public (GRIPP2-SF) was used to report on involvement of patient-partners.
    RESULTS: A total of 55 interactions between 25 parent-partners and the PPM were documented between May 2018 and June 2021. The PPM's support and liaison role contributed to adaptation of meeting schedules for parent-partners, amendment of the compensation guidelines, and ensuring that internal surveys and the newsletter were more accessible and engaging. The PPM also facilitated community-building by keeping parent-partners connected with researchers in the Network. Families and caregivers in the Network were comfortable sharing their experiences and emotions with the PPM who was also a parent herself, allowing researchers and the Network to learn more about parents' experiences in partnering with them and how to improve engagement.
    CONCLUSIONS: We highlight the important complementary role that a PPM can play in enhancing patient engagement in research by better understanding the experiences and needs of parent-partners.
    Keywords:  Parent peer mentor; Parent-partner; Patient engagement; Patient-oriented research
  3. J Am Soc Nephrol. 2023 Sep 06.
      BACKGROUND: Electrolyte reabsorption in the kidney has a high energy demand. Proximal and distal tubular epithelial cells therefore have a high mitochondrial density for energy release. Recently, electrolyte disorders have been reported as the primary presentation of some mitochondrial cytopathies. However, the prevalence and the pathophysiology of electrolyte disturbances in mitochondrial disease are unknown. Therefore, we systematically investigated electrolyte disorders in patients with mitochondrial cytopathies.METHODS: We searched PubMed, EMBASE and Google Scholar for articles on genetically confirmed mitochondrial disease in patients for whom at least one electrolyte is reported. Patients with a known second genetic anomaly were excluded. We evaluated 214 case series and reports (362 patients) as well as 9 observational studies. Joanna Briggs Institute criteria were used to evaluate quality of included studies.
    RESULTS: Of 362 reported patients, 289 had an electrolyte disorder, with, the disorder the presenting or main symptom in 38 patients. The average number of different electrolyte abnormalities per patient ranged from 2.4 to 1.0, depending on genotype. Patients with mitochondrial DNA structural variants seemed most affected. Reported pathophysiological mechanisms included renal tubulopathies and hormonal, gastrointestinal, and iatrogenic causes.
    CONCLUSIONS: Mitochondrial diseases should be considered in the evaluation of unexplained electrolyte disorders. Furthermore, clinicians should be aware of electrolyte abnormalities in mitochondrial disease patients.
  4. BMB Rep. 2023 Sep 08. pii: 5966. [Epub ahead of print]
      Mitochondrial transplantation is a promising therapeutic approach for the treatment of mitochondrial diseases caused by mutations in mitochondrial DNA, as well as several metabolic and neurological disorders. Animal studies have shown that mitochondrial transplantation can improve cellular energy metabolism, restore mitochondrial function, and prevent cell death. However, challenges need to be addressed, such as the delivery of functional mitochondria to the correct cells in the body, and the long-term stability and function of the transplanted mitochondria. Researchers are exploring new methods for mitochondrial transplantation, including the use of nanoparticles or CRISPR gene editing. Mechanisms underlying the integration and function of transplanted mitochondria are complex and not fully understood, but research has revealed some key factors that play a role. While the safety and efficacy of mitochondrial transplantation have been investigated in animal models and human trials, more research is needed to optimize delivery methods and evaluate long-term safety and efficacy. Clinical trials using mitochondrial transplantation have shown mixed results, highlighting the need for further research in this area. In conclusion, although mitochondrial transplantation holds significant potential for the treatment of various diseases, more work is needed to overcome challenges and evaluate its safety and efficacy in human trials.
  5. Int J Mol Sci. 2023 Aug 30. pii: 13478. [Epub ahead of print]24(17):
      The m.3243A>G mutation in the tRNA Leu(UUR) gene (MT-TL1) is one of the most common pathogenic point mutations in human mtDNA. Patient symptoms vary widely and the severity of the disease ranges from asymptomatic to lethal. The reason for the high heterogeneity of m.3243A>G-associated disease is still unknown, and the treatment options are limited, with only supportive interventions available. Furthermore, the heteroplasmic nature of the m.3243A>G mutation and lack of specific animal models of mtDNA mutations have challenged the study of m.3243A>G, and, besides patient data, only cell models have been available for studies. The most commonly used cell models are patient derived, such as fibroblasts and induced pluripotent stem cell (iPSC)-derived models, and cybrid models where the mutant DNA is transferred to an acceptor cell. Studies on cell models have revealed cell-type-specific effects of the m.3243A>G mutation and that the tolerance for this mutation varies between cell types and between patients. In this review, we summarize the literature on the effects of m.3243A>G in cell models.
    Keywords:  cell model; cybrid cell; heteroplasmy; iPSC; m.3243A>G; mitochondria; mtDNA
  6. Intractable Rare Dis Res. 2023 Aug;12(3): 148-160
      Rare diseases are diseases that occur at low prevalence, and most of them are chronic and serious diseases that are often life-threatening. Currently, there is no unified definition for rare diseases. The diagnosis, treatment, and research of rare diseases have become the focus of medicine and biopharmacology, as well as the breakthrough point of clinical and basic research. Birth defects are the hard-hit area of rare diseases and the frontiers of its research. Since most of these defects have a genetic basis, early screening and diagnosis have important scientific value and social significance for the prevention and control of such diseases. At present, there is no effective treatment for most rare diseases, but progress in prenatal diagnosis and screening can prevent the occurrence of diseases and help prevent and treat rare diseases. This article discusses the progress in genetic-related birth defects and rare diseases.
    Keywords:  birth defects; diagnosis; prevention and control; rare diseases; treatment
  7. Hear Res. 2023 Aug 22. pii: S0378-5955(23)00188-0. [Epub ahead of print]438 108876
      Mitochondrial encephalomyopathy is a multi-system disorder mostly caused by inborn errors of the oxidative phosphorylation (OXPHOS) system and usually manifested as complex neurological disorder and muscle weakness. Myoclonic epilepsy with ragged-red fibers (MERRF) syndrome is one of the major subtypes of mitochondrial disease associated with the m.8344A>G mutation in mitochondrial tRNALys gene. In addition to the symptoms in central nervous and muscle systems, a portion of the patients may develop hearing loss, which has been linked to the genetic mutations of mitochondrial DNA (mtDNA) especially in the mitochondrial ribosome RNA (rRNA) gene. Despite a great number of studies focusing on the consequences of mtDNA mutations, the mechanism of pathogenesis of these overt diseases has remained unclear, and there is no specific and effective treatment for MERRF syndromes. In this study, we developed a high-quality mtDNA sequencing method by next generation sequencing technology to search for the additional pathogenic variations of mtDNA from skin fibroblasts of four members in a Taiwanese family with MERRF syndrome. Through uncovering the signatures of all mtDNA variants in the MERRF family, we identified novel mtDNA variants in the genes encoding mitochondrial 12S and 16S rRNAs. The finding from this study will give us further insight into the molecular mechanisms driving the phenotypic variability and timing of onset of the MERRF syndrome.
    Keywords:  MERRF; MTRNR1; MTRNR2; Mitochondrial DNA; Next generation sequencing; Sensorineural hearing loss
  8. Orphanet J Rare Dis. 2023 Sep 04. 18(1): 267
      BACKGROUND: Estimates of rare disease (RD) population impact in terms of number of affected patients and accurate disease definition is hampered by their under-representation in current coding systems. This study tested the use of a specific RD codification system (ORPHAcodes) in five European countries/regions (Czech Republic, Malta, Romania, Spain, Veneto region-Italy) across different data sources over the period January 2019-September 2021.RESULTS: Overall, 3133 ORPHAcodes were used to describe RD diagnoses, mainly corresponding to the disease/subtype of disease aggregation level of the Orphanet classification (82.2%). More than half of the ORPHAcodes (53.6%) described diseases having a very low prevalence (< 1 case per million), and most commonly captured rare developmental defects during embryogenesis (31.3%) and rare neurological diseases (17.6%). ORPHAcodes described disease entities more precisely than corresponding ICD-10 codes in 83.4% of cases.
    CONCLUSIONS: ORPHAcodes were found to be a versatile resource for the coding of RD, able to assure easiness of use and inter-country comparability across population and hospital databases. Future research on the impact of ORPHAcoding as to the impact of numbers of RD patients with improved coding in health information systems is needed to inform on the real magnitude of this public health issue.
    Keywords:  Coding; Diagnoses; Epidemiology; ICD-10; ORPHAcodes; Orphanet; Public health; Rare diseases
  9. J Med Ethics. 2023 Sep 06. pii: jme-2022-108867. [Epub ahead of print]
      This paper problematises the notions of public or common good as weighed against individual sovereignty in the context of medical research by focusing on genetic research. We propose the notion of collective good as the good of the particular collective in which the research was conducted. We conducted documentary and interview-based research with participant representatives and research leaders concerned with participant involvement in leading genetic research projects and around two recent genetic data controversies: the case of the UK Wellcome Sanger Institute, accused of planning unauthorised commercialisation of African DNA samples, and the case of the company Genuity Science, which planned genetic research on brain tumour samples in Ireland with no explicit patient consent. We advocate for greater specificity in circumscribing the collective to which genetic research relates and for greater efforts in including representatives of this collective as research coleaders in order to enable a more inclusive framing of the good arising from such research. Such community-based participant cogovernance and coleadership in genetic research is vital especially when minorities or vulnerable groups are involved, and it centrally requires community capacity building to help collectives articulate their own notions of the collective good.
    Keywords:  Ethics- Medical; Ethics- Research; Genetic Privacy; Informed Consent; Minority Groups