Activities of daily living (ADLs)

Activities and skills related to caring for oneself, such as bathing and showering, feeding, dressing, etc.


Able to walk


A condition where the heart beats in an irregular or abnormal rhythm.


Loss of coordination in muscles that can cause unsteady walking, difficulty writing and grasping objects, and other symptoms.


A condition of the heart characterized by thickening of the heart muscle that weakens heart function over time.

Clinical diagnosis

Diagnosis made on the basis of medical signs, results of medical tests, and patient-reported symptoms.


Difficulty of speech; slow, slurred speech.


Difficulty swallowing.


Shortness of breath; in FA, this condition often occurs in conjunction with cardiac insufficiency.

Ejection Fraction (EF)

Percentage of blood pumped from the heart with each heartbeat; normal EF is usually in the range of 55-70%.

Genetic diagnosis

Laboratory analysis of DNA to aid in the clinical diagnosis of disease; genetic testing can confirm a diagnosis or help predict likelihood of developing symptoms before they appear.


Measurement in diabetes of glycated hemoglobin over a 3-month time period; normal =< 5.6%

Natural History

Description of the progression of disease over time.

Pes cavus

A condition where the feet have a very high arch.


Awareness of the position of the body and the strength of movement being employed. People with FA have a lack of proprioception in that when their eyes are closed or they are in low light conditions, they are often not able to maintain stability.


Abnormal curvature of the spine.



Different forms, or copies, of the same gene. Most genes have two alleles in a person because one allele is inherited from mom and one allele is inherited from dad.


Deoxyribonucleic acid; double-helix (double-stranded) molecules that contain genetic instructions; transcribed to RNA.


Someone who carries one mutated copy and one normal copy of the gene that causes a recessive genetic disease. Everyone has two copies of every gene. In recessive diseases like FA, a person is affected if both copies of their FXN gene are mutated. Parents of someone with FA are carriers who have one mutated FXN gene and one normal FXN gene.


The region within a gene that directly codes for a protein.


Region of DNA that is a molecular unit of inheritance; the gene for FA is frataxin (FXN).


Genetic makeup of an individual organism.


Having two different alleles, or copies, of a gene.


Having two of the same alleles, or copies, of a gene.


The region within a gene that does not directly code for a protein but may have regulatory functions.

Loss of function mutation

A mutation in a gene that causes the gene to not work as well as normal or produce less protein than it should.


The physical manifestation of our genes; symptoms of a condition.

Point mutation

A change in a single letter of DNA which may/may not affect protein structure.


Ribonucleic acid; single-stranded molecules that contain genetic code and control gene expression; mRNA is translated to proteins.

Triplet Repeat Expansion

All genes are composed of a genetic alphabet containing 4 letters: C, G, A, and T. The spelling of the FXN gene includes a repetition of the three letters “GAA.” People unaffected by FA usually have between 7 and 30 GAA repeats in the FXN gene. FA is caused when this stretch of GAA’s is expanded, usually to over 100 repeats.

Friedreich’s Ataxia (FA)


Friedreich’s Ataxia (FA is more commonly accepted; FRDA is a clinical designation for FA and is often used in medical publications).


Frataxin gene


Protein produced by FXN gene.


Steady state of physical and chemical conditions maintained by living systems; self-regulating processes to maintain stable functioning and survival; examples include blood pressure and body temperature. In FA, iron homeostasis is out of balance in the mitochondria, resulting in too much iron accumulation within cells.


Energy producing units within cells; produce ATP for cellular function.

Research and Clinical Trials

Adverse Events (AE)

An unexpected medical problem that happens during a trial. May be mild, moderate, or severe. This may be caused  by the drug or therapy being given or be a medical complication not associated with the drug or therapy.


A minor’s agreement to participate in a clinical study or trial. Minors cannot provide legal informed consent, but they can be asked to give assent in addition to the legal consent provided by their parents or legal guardians. Assent is typically sought between the ages of 7 to 17 but this can vary by institution.


(See cohort). Any of the groups in a randomized trial (e.g. treatment group or placebo group)


Information gathered from each participant at the start of the trial and used as a point of comparison after treatment or intervention. The information might include a neurological assessment such as the mFARS, basic laboratory (blood work) tests, and patient-reported assessments.

Biologic License Application (BLA)

Biologic License Application. An approved BLA allows a sponsor to sell a biologic therapy (proteins, antibodies, vaccines, gene therapy, etc.) and licensed prescribers to prescribe it to patients.

Biologic Therapy

A therapy that uses substances derived from living organisms such as cells, proteins, antibodies, and genetic materials (gene therapy).


A biological measure or molecule that can be captured through imaging or found in blood, other body fluids, or tissues as a sign of a normal or abnormal process or an indicator of disease; may be measured to see how the body responds to a treatment for a disease.


Center for Biologics Evaluation and Research; in the United States, the arm of the FDA that regulates biological therapies and reviews Biologic License Applications.


Center for Drugs Evaluations and Research; in the United States, the arm of the FDA that regulates over the counter and prescription drugs and reviews New Drug Applications.

Clinical Outcome Assessment (COA)

Measures how a patient feels or functions and is used to determine whether a treatment has demonstrated a benefit.


A group of patients who all receive the same treatment or intervention. For example, in dose-administered trials, a different cohort, or group, is enrolled at each dose level. The number of participants in each cohort is determined for each trial protocol. A group of people who participate in the study together. They may be in different study arms but the same cohort.

Clinical Research Unit (CRU)

This is the space where investigators conduct clinical research.

Clinical Study

Also called an observational study; an investigation to observe, measure, and describe a disease that may involve observing the progression of the disease over time (natural history study) or measuring biomarkers.

Clinical Trial

An investigation to explore if a medical intervention, such as a medical strategy, drug, or device, is safe and effective for humans.

Compassionate Use

In the United States, this term is interchangeable with “expanded access.” Compassionate use and expanded access describe a process in which a patient with a serious or immediately life-threatening condition may be able to gain access to an investigational therapeutic (drug or medical product) without enrolling in the clinical trial investigating the therapeutic. This typically occurs when there are no satisfactory avenues of approved treatment available. Compassionate use/expanded access of a therapeutic for an individual must be approved by both the FDA and the biopharmaceutical company running the trial. In Europe, compassionate use and expanded access describe two different processes an individual can engage in to seek access to an investigational therapeutic, but these terms and processes vary country by country.


Participants who receive placebo initially but have access to treatment later in the trial.

Data Safety & Monitoring Board (DSMB)

Independent group of research experts established by the trial sponsor who ensure the study is being done safely and is meeting performance endpoints. The DSMB can recommend the sponsor modify the parameters of the study or stop the trial.

Delayed Start

Individuals either get randomized to treatment at the outset of the study or delayed to start treatment at a specified time.


All participants, investigators, health care providers, and sponsors are unaware of which study arm the participant is in. None of them know which treatment (or placebo) a participant is receiving.


The ability of a treatment, device, or medication to produce a desired effect on the patient population.

Efficacy Study

A phase 2 or phase 3 clinical trial that’s designed to determine whether the drug or treatment works in treating a specific symptom.


The European Medicines Agency (EMA) is a decentralised agency of the European Union (EU) responsible for the scientific evaluation, supervision and safety monitoring of medicines in the EU.


The planned measure(s) that are important for evaluating the safety or the effect of a treatment. Primary and secondary endpoints are defined before the trial begins.

Exclusion Criteria

A list of features that exclude a patient from being in a study. This can include things such as a person’s age, sex, use of specific medications, or presence of specific symptoms or disease manifestations. For example, a study researching biomarkers in children with FA through MRI may exclude individuals over the age of 18 and individuals who have implantable medical devices not compatible with MRI scans. Exclusion criteria can also be related to logistics of a study. For example, some studies based in the United States may exclude participants who do not speak English or who are not able to stay at the study site for an extended period.

Expanded Access

See compassionate use.

Ex vivo

Procedure where organ, tissue, or cells are taken from a living organism, treated, and then returned to the living body; this is one way to deliver gene therapy.

FA Global Clinical Consortium (FA GCC)

An international group of clinical research centers that work together to advance treatments and clinical care for individuals with Friedreich’s Ataxia.


(m=Modified) Friedreich’s Ataxia Rating Scale – a neurological assessment used in clinical research or trials that measures upper and lower limb coordination, upright stability, bulbar function, and peripheral nervous system function.


Food and Drug Administration; regulates the drug development and approval process in the United States.

First in Human Study

A Phase I trial when a new drug is tested in people for the first time. The treatment would have been tested in cells and animals but not yet in humans. The very first dose is called the Sentinel Dose. The aim is to find the safe dose range.

Gene editing

Methodology to directly change the sequence of DNA within a gene to correct genetic disorders.

Gene therapy

The transfer of a normal copy of a gene into cells to replace missing or defective genes to correct genetic disorders.


The time required for a drug concentration to reach half its original value in the body. Half-life is a reflection of how quickly the drug is eliminated from the body.

Inclusion Criteria

A list of criteria a person must meet to be included in a study. This can include a person’s age, sex, or presence of specific symptoms or disease manifestations. For example, a study researching biomarkers in children with FA through MRI may require participants to be under 18 years of age and have a confirmed genetic diagnosis of FA. Inclusion criteria can also be related to logistics of a study. For example, some studies based in the United States may require participants to speak English or be willing to stay at the study site for an extended period.

Informed Consent

Consent granted by an individual or their legal guardian to participate in a trial. Informed consent can be granted only after a clinician or researcher has provided education on the study protocol and possible risks and benefits of participating in the study, and answered all questions the participant or their legal guardians may have. The legal age of consent is 18 years.

Interventional Study

An experiment that tests if a new drug, device, intervention, or treatment is safe and/or effective.

Investigational New Drug Application (IND)

The IND allows the sponsor (biopharmaceutical company or research institution) to perform clinical trials on an investigational drug in a specified population, in the US. In Europe, it is called a Clinical Trial Application or CTA. More specifically, clinical trials cannot be done without a relevant IND in effect in the US and a CTA in Europe.

Institutional Review Board (IRB)

An independent committee responsible for reviewing a clinical trial protocol. The function of the IRB is to protect the rights of the participants and to ensure the study is done in a safe and ethical manner.

Investigator Initiated Study

Physician or academic researcher initiates and conducts a study. No biopharmaceutical industry sponsor.

In vitro

Studies performed on biological material (cells, tissues) outside their normal biological environment; opposite of in vivo; allows for control over what is introduced during the study to assess the outcome; this term describes type of studies performed during pre-clinical research.

In vivo

Studies performed within a living organism (animals, humans); opposite of in vitro; clinical trials in humans and research on animal models are both considered in vivo studies.

Mechanism of Action

How a drug or biological medical product works at the molecular level to produce the observed effects on a given symptom or disease outcome.


The Medicines and Healthcare products Regulatory Agency (MHRA) regulates medicines, medical devices and blood components for transfusion in the UK.

Multiple Ascending Dose (MAD) Study

Participants in a cohort receive a dose multiple times. If there are minimal side effects, a new cohort receives a higher dose multiple times.

Natural History Study

Research studies that collect information on how a disease naturally progresses or changes over time with standard of care treatment. Natural history studies follow a group of patients over time and record different types of health information including symptoms, performances on functional tests, and results of imaging, blood work, or other laboratory tests. Data from natural history studies can be used as a comparison to data from clinical trials to help determine how much benefit the clinical trial therapeutic has on health outcomes in comparison to standard of care treatment.


National Center for Advancing Translational Sciences; part of NIH.

New Drug Application (NDA)

An approved NDA allows a sponsor to sell a drug and licensed prescribers to prescribe it.


The National Institutes of Health (NIH), a part of the U.S. Department of Health and Human Services, is the nation’s medical research agency.

Observational Study

Also called a clinical study; an investigation to observe, measure, and describe a disease that may involve observing the progression of the disease over time (natural history study) or measuring biomarkers.


Short DNA or RNA molecules, that have a wide range of applications in genetic testing, research, and therapeutics.

Open Label

A study where the patient, physician and study coordinator are informed of the drug/dose being administered to study participants. Some studies will start as a randomized, placebo-controlled and then offer participants to enroll in an “open label extension” where all participants are on drug and safety and efficacy data are still collected.

Oxidative stress

Imbalance between the production of free radicals and the ability of the body to counteract or detoxify their harmful effects through neutralization by antioxidants. A free radical is an oxygen containing molecule that has one or more unpaired electrons, making it highly reactive with other molecules. In FA, there are more free radicals than the body can detoxify which leads to cellular damage.


Probability value; defines statistical significance; the lower the p-value (usually <0.05), the greater the likelihood the result/outcome did not happen by random chance.


A drug’s maximum biological effect.

Pharmacodynamics (PD)

Biochemical and physiological effects; relationship of drug concentration and biological effect.

Pharmacokinetics (PK)

Measurements of how a drug is absorbed, distributed throughout the body, metabolized, and eliminated.


A substance that has no expected therapeutic effect; used as a control within clinical research for comparison to what is being evaluated in the study.

Placebo-Controlled Study

There are two (or more) groups (Study Arms). One group gets the active treatment, the other gets the placebo. Everything else is the same between the two groups. Any difference in outcome measures or safety is attributed to the active treatment.

Patient reported outcomes (PROs)

Description directly from a patient about his/her own health status that ideally implicates the symptoms that are most meaningful for targets of drug development.

Prospective study

Researchers determine an outcome by following groups of people over time after a drug is administered or by recording medical and/or lifestyle changes. (See retrospective study for comparison).

Randomized controlled study

Clinical study that randomly (by chance) assigns participants to two or more groups of observation or treatment; double-blind randomized controlled study is a study where neither the participants nor the investigators know who is getting the drug and who is getting the placebo to avoid bias in interpreting observations and measurements.

Registration Study

Clinical trial intended to provide sufficient data to support the filing of an Approval with a regulatory agency.

Retrospective study

Researchers already know the outcome and are searching for the correlation, influencing factors, or cause by reviewing past data (e.g., medical records).

Safety Study

Establishes safety in either the short- or long-term. Or, if a drug is being repurposed, confirms the safety in the targeted disease.

Serious adverse event (SAE)

Any adverse event that 1) results in death, 2) is life threatening, 3) requires hospitalization or prolongation of hospitalization, 4) results in persistent or significant disability/incapacity, or 5) results in a congenital anomaly/birth defect. SAEs can occur during evaluation of a potential treatment – drug or medical device – and must be reported to FDA.

Single Ascending Dose (SAD)

Participants in a cohort receive a dose, one time. If there are minimal side effects, a new cohort receives a single higher dose.

Single Blind Study

A study in which the researchers or clinicians running the study are aware of which participants are receiving placebo or the experimental therapeutic, but the individual participants do not know whether they are receiving placebo or experimental therapeutic.


The pharma/biotech company or academic institution that oversees the study and takes responsibility for the operations, management and financing of the trial/study.

Statistical significance

Defines numerical data where it is very unlikely that the result (outcome) occurred by random chance.

Study Protocol

The written description of a clinical trial or study that details the study design, timeline, goals, endpoints, and inclusion and exclusion criteria.

Surrogate Endpoint

An indicator or sign used in place of another to determine if an experimental treatment works. Surrogate endpoints do not guarantee that a treatment works, but they can give an earlier indication that the therapy is reasonably likely to have benefit. For example, changes in frataxin levels in the blood could be used as a surrogate endpoint in place of changes in neurological function.


Discontinuing a trial before completion. Can be at a site or the entire study. Can be the decision of the sponsor, site, IRB, or regulatory agency.


Therapeutic Goods Administration (TGA), is Australia’s government authority responsible for evaluating, assessing and monitoring products that are defined as therapeutic goods. TGA regulates medicines, medical devices and biologicals to help Australians stay healthy and safe.


The degree to which the adverse effects from a drug or treatment can be tolerated by participants.


Biological vehicle used to deliver gene therapy to cells (ex. viruses).


A period of time that participants need to stop an ongoing treatment before becoming eligible for a trial or for the next part of a trial.


An individual discontinuing participation in a trial. The participant may choose to withdraw, or the investigators may require the participant to stop.