Mitochondrial Diseases

The main goal of the project is provision of a global registry for mitochondrial disorders to harmonize previous national registries, enable world-wide participation and facilitate natural history studies, definition of outcome measures and conduction of clinical trials.

This prospective observational cohort study investigates the subset-specific metabolic adaptation and functional remodeling of cytotoxic γδT cells in critically ill patients with and without sepsis. Emerging evidence indicates that γδT cells, as a bridge between innate and adaptive immunity, play a critical role in early anti-infection defense during sepsis. However, the functional status and underlying regulatory mechanisms of cytotoxic γδT cells in septic patients remain incompletely understood. Our preliminary single-cell transcriptomic analysis revealed that cytotoxic γδT cells from septic patients exhibit significant alterations in cytotoxicity-associated molecules (GZMB, PRF1, GNLY) and mitochondrial oxidative phosphorylation (OXPHOS) pathway genes, particularly COX6C, which correlates with cytotoxic effector molecule expression. This study aims to systematically characterize the proportion, cytotoxicity, and mitochondrial metabolic function of circulating cytotoxic γδT cells across three cohorts: healthy controls, critically ill non-septic patients, and critically ill septic patients. By integrating flow cytometry, mitochondrial function assays, and functional validation experiments, we seek to elucidate the role of COX6C-mediated mitochondrial metabolic abnormalities in cytotoxic γδT cell dysfunction, providing theoretical basis for understanding immune dysregulation in sepsis and identifying novel therapeutic targets.

The KHENERFIN study aims to determine whether the study medicine, sonlicromanol, is able to reduce symptoms of fatigue and the impact of fatigue on daily life, and whether sonlicromanol is able to improve physical abilities of people like balance control and lower limb skeletal muscle strength in people with mitochondrial disease. In this study, the effects of sonlicromanol are compared against a placebo, a tablet identical in appearance and taste but without the active drug. Participants take either sonlicromanol or placebo twice daily for a treatment duration of 52 weeks. In addition to these primary objectives, the study evaluates the efficacy of sonlicromanol on secondary and exploratory outcomes, as well as its safety and tolerability after one year of treatment.

The study involves up to 5 visits for a fasting blood draw, behavioral assessments, and/or questionnaires. Other samples may be collected when appropriate. This study is currently recruiting. There is no cost for visits or study-related exams.

The Natural History of Mitochondrial (MITO) Diseases (a longitudinal study observing the natural history of mitochondrial diseases) The goal of this observational study (non-randomised retrospective and prospective) is to fully characterise primary MITO disease; that includes both sexes/genders, over 18 years of age and healthy volunteers\]. The main question\[s\] it aims to answer is to: • better characterise MITO phenotypes (organ involvement, severity, progression) and collect biospecimens to create a biobank that can be used for future biomarker discovery to improve early diagnosis, prognostication and management of mitochondrial disease. The study will be a longitudinal, retrospective, prospective, observational study of participants (400) with confirmed MITO and relevant controls followed for up to 10 years. Data will be collected at regularly scheduled standard-of-care (SOC), 6 to 12 monthly appointments. The 100 control participants will therefore be comprised of (i) unaffected asymptomatic family members of MITO participants with no genetic risk; (ii) participants with non-MITO movement disorders that are not classified as MITO by their clinical presentation and genetic tests (for example Parkinson's disease) and/or (iii) age-matched healthy controls recruited from the NeuRA database of volunteers. Demographic data, medical history, biochemical, histological, genetic, social and other clinical SOC data will be collected. Additionally, seizure and migraine frequency in participants who experience these, will be collected and a quality-of-life questionnaire (SF-12v2), as part of the validated neurological assessment using the Newcastle Mitochondrial Disease Adult Scale (NMDAS).

The purpose of this study is to investigate if the study medicine, KL1333, is safe, well-tolerated and effective long-term in improving the symptoms of fatigue and impacts on daily living and functional capacity (physical abilities) in people with PMD.

The goal of this observational study is to learn how exercise training affects molecular processes in skeletal muscle in adults with mitochondrial myopathy, compared with healthy adults. The main questions it aims to answer are: * How does exercise training affect mitochondrial activity and energy production pathways in skeletal muscle in people with mitochondrial myopathy? * How does exercise training affect molecular signals related to muscle growth, stress responses, and muscle-nerve communication in people with mitochondrial myopathy? Researchers will compare the trained leg to the untrained leg within the same participant, and also compare responses between participants with mitochondrial myopathy and healthy control participants, to see how molecular responses to exercise differ between groups. The participants will: * Complete a 3-4-week supervised exercise training program using one leg. * Undergo muscle biopsies from both the trained and untrained leg. * Complete basic muscle strength and physical function tests.

Diabetes can lead to heart failure independently, but the underlying causes remain incompletely understood. The main aim of this study is to identify differential regulation of mitochondrial substrate utilization and complex activity in heart failure and type 2 diabetes mellitus (T2DM). For this, we will conduct a prospective, observational study to examine myocardial mitochondrial oxidative function and related metabolic parameters, gene expression, histological markers, and inflammation in cardiac tissue from patients with heart failure or patients after heart transplantation. We will further assess cardiac function using cardiac magnetic resonance imaging with and without stress protocols and magnetic resonance spectroscopy. Glycemic control/T2DM will be characterized by oral glucose tolerance tests. The results of this project will help to better understand the cellular mechanisms of the development of diabetic cardiomyopathy and contribute to the development of early diagnostic, as well as therapeutic approaches for the prevention and treatment of diabetic cardiomyopathy.

Past mitochondrial disease treatment studies have been unsuccessful in determining treatment efficacy, and a major factor has been the lack of validated biomarkers in mitochondrial myopathy (MM). There is currently a growing number of potential new treatments to be tested through MM clinical intervention trials, which has created a pressing need for quantitative biomarkers that reliably reflect MM disease severity, progression, and therapeutic response. The purpose of the study is to measure the efficacy of an electrochemical oxygen nanosensor to measure in vivo mitochondrial function in human muscle tissue, and its ability to discriminate MM patients from healthy volunteers. The data and results from this nanosensor study may contribute to current and future research, including improved diagnostic and therapeutic approaches for patients with mitochondrial disease.

The North American Mitochondrial Disease Consortium (NAMDC) maintains a patient contact registry and tissue biorepository for patients with mitochondrial disorders.

This is a multi-aim study, studying the effects of conventional exercise (measured through Cardiopulomary Exercises Testing or an in-bed pedal exercise) and passive exercise through periodic acceleration (pGz). Aim 1 will focus on the differences between primary mitochondrial disease (PMD) patients and healthy volunteers. Aim 2 is an exploratory aim, which will be studying the effects in patients admitted to the Children's Hospital of Philadelphia Pediatric Intensive Care Unit (PICU).

The Investigator proposes to record the fetal and postnatal development of children conceived using Mitochondrial Donation (MD) and to perform expert assessment of development at 18 months (corrected for gestational age) using the internationally validated Bayley-III developmental assessment tool.

Primary Mitochondrial diseases are a clinically and genetically heterogeneous group of disorders caused by mutations in genes encoded by nuclear Deoxyribonucleic Acid (DNA) or by mutations and/or deletions in the mitochondrial DNA (mtDNA). While some mitochondrial disorders only affect a single organ (e.g., the eye in Leber hereditary optic neuropathy \[LHON\]), many involve multiple organs. Mitochondrial disorders may present at any age and a frequent feature is the increasing number of organs involved in the course of the disease. Minovia Therapeutics Ltd. ("Minovia") is a biotech company developing novel therapeutics based on its mitochondrial augmentation technology (MAT). MNV-201 is a cell therapy produced by MAT that consists of the participant's autologous CD34+ hematopoietic stem and progenitor cells (HSPCs) enriched with allogeneic placental-derived mitochondria, manufactured in Minovia's GMP facility.

The main goal of the project is provision of a global registry for mitochondrial disorders to harmonize previous national registries, enable world-wide participation and facilitate natural history studies, definition of outcome measures and conduction of clinical trials.

Mitochondrial DNA (mtDNA) depletion syndromes (MDS) are a genetically and clinically heterogeneous group of autosomal recessive disorders that are characterized by a severe reduction in mtDNA content leading to impaired energy production in affected tissues and organs. MDS are due to defects in mtDNA maintenance caused by mutations in nuclear genes that function in either mitochondrial nucleotide synthesis. MDS are phenotypically heterogeneous and usually classified as myopathic, encephalomyopathic, hepatocerebral or neurogastrointestinal. No efficacious therapy is available for any of these disorders. Affected individuals should have a comprehensive evaluation to assess the degree of involvement of different systems. Treatment is directed mainly toward providing symptomatic management. No treatment for MDS. Clinical trials studies and in vitro/in vivo research studies showed that the enhancement of the salvage pathway by increasing the availability of deoxyribonucleosides needed for each specific genetic defect prevents mtDNA depletion. Early recognition and immediate therapy to restore mitochondrial function could potentially improve clinical course. Confirming the benefit of deoxynucleosides as a safe and potentially efficacious therapy, will lead to the availability of the first specific and effective treatment for Mitochondria Depletion Disorders. In this phase II Trial a mix of Deoxynucleosides Pyrimidine (Deoxycytidine dC and Deoxythymidine dT) will be used as early treatment of MDS. The dose used has been already used in other clinical trials, and appears to effective and well-tolerated. The subjects included are children (0-18Y), with positive MDS diagnosis and express mutations in one of the following genes: POLG, POLG2, C10orf2, RRM2B, MPV17, SUCLA2, SUCLG1, FBXL4, DTYMK. Subjects with MDS expressing neurological phenotypes dysfunction.

CoRDS, or the Coordination of Rare Diseases at Sanford, is based at Sanford Research in Sioux Falls, South Dakota. It provides researchers with a centralized, international patient registry for all rare diseases. This program allows patients and researchers to connect as easily as possible to help advance treatments and cures for rare diseases. The CoRDS team works with patient advocacy groups, individuals and researchers to help in the advancement of research in over 7,000 rare diseases. The registry is free for patients to enroll and researchers to access. Visit sanfordresearch.org/CoRDS to enroll.

Next-generation sequencing (NGS), and in particular whole exome sequencing (WES) or genome sequencing (WGS), has enabled a significant technical advance that has considerably improved genetic diagnostics. However, around 50% of patients still remain undiagnosed and are in diagnostic limbo. One of the causes of this is pathogenic variants that modify transcript expression and/or RNA splicing. These variants may be located in deep intronic or intergenic regions, or in the coding sequence, synonymous or missense variants, also having pathogenic consequences on splicing or gene expression. It is very often difficult to interpret the pathogenicity of these variants, which often remain variants of uncertain significance (VSI). The usefulness of transcriptome sequencing (RNA-seq) in the genetic diagnosis of MM has been demonstrated in recent years by several teams with diagnostic yields of 10% to 35%. These studies are ideally performed using muscle tissue, as MMs are most often expressed in tissues with high energy metabolism such as muscle, heart, brain or liver. However, as biopsies of these tissues are difficult to obtain, most transcript studies are performed using fibroblasts obtained from skin biopsies. Indeed, extreme regulatory defects such as loss of expression or aberrant splicing can be detected in fibroblasts, even though the physiological consequence on fibroblasts may be negligible. However, some patients also refuse these biopsies and may remain in diagnostic limbo in the absence of functional analysis to confirm the pathogenicity of the variants identified. RNA studies can also be performed using RNA extracted from blood cells on PAXGene tubes. The quantity of RNA extracted is lower than that extracted from fibroblasts, but this type of analysis avoids a more invasive procedure, saves technical time by avoiding the manips associated with cell culture, and saves time for the patient by enabling immediate extraction from the blood tube without waiting for cell culture. Frésard et al showed in patients with 16 different Mendelian pathologies that RNA-seq on blood cells identified a diagnosis in 7.5% of patients tested. Their approach revealed both expression variations and splicing anomalies. The investigators therefore propose to carry out a transcript study using high-throughput RNA sequencing (RNA-Seq), in parallel on RNA extracted from fibroblasts and on RNA extracted from blood cells, on 10 patients with suspected mitochondrial disease in whom variants of uncertain significance in candidate genes (VSI+) have been identified. The investigators chose to target our study on patients with VSI+, previously identified by NGS, to facilitate interpretation of the RNA-Seq data within the framework of a "pilot" study. In these patients, who carry variants in candidate genes, the investigators will focus our bioinformatics analysis on these genes. For the interpretation of VSI+, a targeted approach using Sanger sequencing based on RT-PCR, or quantification of gene expression using quantitative PCR, is also feasible, but requires custom development for each variant, which is very time-consuming and not insignificantly expensive. The advantage of an RNA-seq approach is that it homogenizes the diagnostic strategy for patients, saves analysis time and therefore reduces the time spent in diagnostic wandering. Finally, the drastic reduction in the cost of NGS sequencing means that this technique could be used routinely as a complement to exome/genome sequencing. It could therefore eventually be applied not only to patients with VSI+ but also, in the absence of evidence of potentially pathogenic variants, as an aid to filtering variants identified by WES/WGS.

MITOMICS aims to determine which RNA-Seq results (from muscle or fibroblasts) are the most informative for the interpretation of VUS identified by WES for patients suspected of mitochondrial myopathy. Analysis of RNA-Seq and WES results will performed with a computational approach using an autoencoder-based method

Choosing to participate in an expanded access program is an important personal decision. Talk with your doctor to learn more about this program. The treating physician must contact StealthBiotherapeutics using the Expanded Access Program Contacts provided. Elamipretide will only be made available after careful review of an individual request submitted by the treating physician. The initiation and conduct of the treatment with elamipretide for an individual patient, and compliance with this treatment guideline, will be under the full and sole responsibility of the treating physician.