Clinical trial NCT04580979: Natural History Study of FDXR Mutation-related Mitochondriopathy
Official title: A Natural History Study of Neurodegeneration and Optic Atrophy Caused by Ferredoxin Reductase Mutations in Pediatric and Adult Patients
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Neurodegenerative Disease, Hereditary
Mitochondrial Diseases
Optic Atrophy
Keywords: Neurodegeneration
Mitochondrial disease
Optic atrophy
Ferredoxin reductase
Iron-sulfur cluster biogenesis
Iron overload
Iron homeostasis
Lead sponsor: State University of New York at Buffalo
Sponsor class: OTHER
Collaborators: name: The Callum McKeefery and Nikki Albano McKeefery Pediatric Division of Genetics Fund
First posted: 2020-10-09
Enrollment: 33
Sex: ALL
Minimum age (years): 0
Maximum age (years): 65
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_ONLY
Time perspective: OTHER
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Primary care clinic

Brief summary: The purpose of the study is to systematically characterize the clinical course of the progressive neuropathy and optic atrophy observe in pediatric and adult patients with biallelic mutations in the ferredoxin reductase gene.

Detailed description: The mitochondrial membrane-associated ferredoxin reductase (FDXR) is a flavoprotein that initiates the mitochondrial electron transport chain by transferring electrons from NADPH to the mitochondrial cytochrome P450 system via the ferredoxins FDX1 or FDX2. In addition to essential roles in Fe-S cluster biogenesis, this pathway is also central to the biosynthesis of steroid hormones. Previously, Dr. Taosheng Huang's research group has identified mutations in the FDXR gene in many individuals who share clinical presentations consistent with a mitochondrial disorder-including ataxia, hypotonia and optic atrophy-and obtained a naturally-occurring Fdxr mutant mouse model from Jackson Lab that corroborated these results (PMID: 29040572 and PMID: 30250212). In particular, FDXR enzyme activity, mitochondrial complex activities and ATP production were all significantly reduced in their patient samples. Their studies further indicated that Fdxr mutation leads to neurodegeneration that is associated with both inflammation as well as the abnormal accumulation of iron in the mitochondria, likely as a result of disrupted Fe-S cluster synthesis. More recently, his group has used the CRISPR-Cas9 system to generate a mouse line with a p.R389W amino acid change, which more precisely matches the most common human variant observed in their patients and shows a much more severe phenotype than their previous, naturally occurring Fdxr mouse model. They have also show that AAV-based gene therapy can significantly improve the condition of Fdxr mutant mice (DOI:https://doi.org/10.1016/j.omtm.2020.05.021), providing valuable preclinical data that may open the door for adapting such gene therapy treatments for use in human clinical trials. Given the recent regulatory approval granted to gene therapy treatments for LCA2, SMA1, and β-thalassemia, there is strong possibility that such an approach will ultimately produce a viable clinical treatment for FDXR patients as well.

FDXR is required for Iron-sulfur (Fe-S) clusters synthesis which is essential for multiple important biological processes, including electron transfer, cofactor synthesis, and gene regulation. Fe-S cluster biosynthesis is a tightly regulated process that requires coordinated delivery of both iron and sulfur and is a cofactor of many proteins. A variety of human disorders have been associated with impaired Fe-S cluster synthesis, including neurodegenerative disorders (e.g. Friedreich's ataxia) and myopathy with lactic acidosis. Iron homeostasis, which requires precise synthesis and localization of Fe-S clusters in mitochondria, is critical to ensure that there is sufficient iron for cellular functions, without reaching toxic levels of iron. Excessive levels of iron favor the formation of excess oxygen free radicals and consequent mitochondrial dysfunction.

The Rare Disease Act and Rare Disease Orphan Product Development Act highlight the importance of rare disease research and the obstacles to developing effective treatments for these diseases. However, the study of rare diseases may open a window to studying other human conditions. For example, Iron-sulfur biosynthesis abnormalities have been observed in more common human diseases such as Friedreich's ataxia. This relationship highlights the importance of human disease research by multiple approaches to understand biological mechanisms and for general application to human health. For these reasons, a better understanding of the pathogenesis of FDXR deficiency may help facilitate our knowledge of disease biology, neurodevelopment, brain function, and other organ abnormalities. Thus, in order to better understand the function of FDXR and to help lay the groundwork for eventual clinical trials of gene therapy or drug-based treatments for FDXR-related disease, the investigators propose this natural history study of both pediatric as well as adult patients with biallelic mutations in the ferredoxin reductase gene.

Eligibility criteria: Inclusion Criteria:

* Patients who are clinically diagnosed with biallelic mutations in the ferredoxin reductase gene
* Male and female patients from 2 to 65 years of age
* Patients who have consented to the study
* In the case of a deceased patient whose parent(s) and/or legal guardian(s) have provided informed consent for study participation, the investigators will review the patient's medical records to determine study eligibility.

Exclusion Criteria:

* Significant postnatal complications or congenital anomalies that are not known to be associated with ferredoxin reductase deficiency
* Patient has received any experimental treatment for ferredoxin reductase deficiency within the 6 months prior to enrollment, or is expected to receive any such therapy during the study period

Primary outcomes:
measure: Custom Medical History Questionnaire for Patients with FDXR Mutation-related Mitochondriopathy
timeFrame: 3 years
measure: Retrospective examination of the medical records of patients with FDXR Mutation-related Mitochondriopathy
timeFrame: 3 years
measure: Eye assessments to evaluate ocular health
timeFrame: 3 years
measure: Growth and development (height)
timeFrame: 3 years
measure: Growth and development (weight)
timeFrame: 3 years
measure: Growth and development (BMI)
timeFrame: 3 years
measure: ACTH stimulation testing for adrenal insufficiency
timeFrame: 3 years
Secondary outcomes:
Other outcomes:
Locations:
city: Buffalo
country: United States
facility: UBMD Pediatrics
state: New York
Study officials:
affiliation: State University of New York at Buffalo
name: Taosheng Huang
role: PRINCIPAL_INVESTIGATOR
References:
citation: Slone J, Peng Y, Chamberlin A, Harris B, Kaylor J, McDonald MT, Lemmon M, El-Dairi MA, Tchapyjnikov D, Gonzalez-Krellwitz LA, Sellars EA, McConkie-Rosell A, Reinholdt LG, Huang T. Biallelic mutations in FDXR cause neurodegeneration associated with inflammation. J Hum Genet. 2018 Dec;63(12):1211-1222. doi: 10.1038/s10038-018-0515-y. Epub 2018 Sep 25.
citation: Slone JD, Yang L, Peng Y, Queme LF, Harris B, Rizzo SJS, Green T, Ryan JL, Jankowski MP, Reinholdt LG, Huang T. Integrated analysis of the molecular pathogenesis of FDXR-associated disease. Cell Death Dis. 2020 Jun 4;11(6):423. doi: 10.1038/s41419-020-2637-3.
citation: Peng Y, Shinde DN, Valencia CA, Mo JS, Rosenfeld J, Truitt Cho M, Chamberlin A, Li Z, Liu J, Gui B, Brockhage R, Basinger A, Alvarez-Leon B, Heydemann P, Magoulas PL, Lewis AM, Scaglia F, Gril S, Chong SC, Bower M, Monaghan KG, Willaert R, Plona MR, Dineen R, Milan F, Hoganson G, Powis Z, Helbig KL, Keller-Ramey J, Harris B, Anderson LC, Green T, Sukoff Rizzo SJ, Kaylor J, Chen J, Guan MX, Sellars E, Sparagana SP, Gibson JB, Reinholdt LG, Tang S, Huang T. Biallelic mutations in the ferredoxin reductase gene cause novel mitochondriopathy with optic atrophy. Hum Mol Genet. 2017 Dec 15;26(24):4937-4950. doi: 10.1093/hmg/ddx377.
citation: Yang L, Slone J, Zou W, Queme LF, Jankowski MP, Yin F, Huang T. Systemic Delivery of AAV-Fdxr Mitigates the Phenotypes of Mitochondrial Disorders in Fdxr Mutant Mice. Mol Ther Methods Clin Dev. 2020 May 22;18:84-97. doi: 10.1016/j.omtm.2020.05.021. eCollection 2020 Sep 11.
citation: Campbell T, Slone J, Metzger H, Liu W, Sacharow S, Yang A, Moosajee M, La Morgia C, Carelli V, Palombo F, Lines MA, Innes AM, Levy RJ, Neilson D, Longo N, Huang T. Clinical study of ferredoxin-reductase-related mitochondriopathy: Genotype-phenotype correlation and proposal of ancestry-based carrier screening in the Mexican population. Genet Med Open. 2023 Nov 11;2:100841. doi: 10.1016/j.gimo.2023.100841. eCollection 2024.