Introduction: When to Seek Diagnostic Testing

If you or someone you care for starts experiencing unusual problems with balance, coordination, or walking that seem to get worse over time, it may be time to see a doctor. Friedreich’s ataxia, often simply called FA, is a rare genetic condition that causes progressive damage to the nervous system, affecting how the body moves and coordinates its actions.^[1]

The first signs of Friedreich’s ataxia typically appear between the ages of 5 and 15, though they can start earlier or much later in life. Children or teenagers might seem clumsy or unsteady when walking, as if they have trouble keeping their balance. They may trip frequently or have difficulty with tasks that require fine control, like writing or buttoning a shirt. These early symptoms are not always easy to spot right away because they can be gradual and subtle.^[3]

It is important to seek diagnostic testing if these movement problems persist or worsen, especially if they are accompanied by other symptoms such as loss of reflexes, slurred speech, or a curving of the spine called scoliosis. Even when symptoms are mild, an early and accurate diagnosis matters. Knowing what is causing these changes allows doctors to provide the right kind of care and support, and helps families plan for the future. The sooner you find out what is happening, the better the response to therapy is likely to be.^[20]

Sometimes, a diagnosis of FA can take several years because early blood tests or imaging studies may not show clear signs of the disease. However, if balance and coordination problems continue, or if new symptoms develop, further testing should be done. Genetic testing is the definitive way to confirm Friedreich’s ataxia, and it is the only method that provides a certain diagnosis.^[4]

Diagnostic Methods for Identifying Friedreich’s Ataxia

Diagnosing Friedreich’s ataxia involves several steps, beginning with a careful review of symptoms and medical history, followed by a variety of tests. Doctors often start by asking detailed questions about when symptoms began, how they have changed, and whether anyone else in the family has had similar problems. This information helps guide the next steps in testing.^[5]

Physical and Neurological Examination

The first hands-on test is usually a physical and neurological examination. During this exam, a doctor checks how well the body moves and responds to different tasks. They may test your balance, ask you to walk in a straight line, or check your reflexes by tapping on your knees or ankles with a small hammer. People with FA often have reduced or absent reflexes, especially in the legs. The doctor may also examine muscle strength, coordination, and the ability to sense where your body is in space, which is called proprioception.^[1]

In addition to these tests, the doctor may look for signs of scoliosis, which is a sideways curve in the spine that affects about 70 percent of people with FA. They may also check for foot deformities, such as high arches, which are common in this condition.^[4]

Blood Tests

One of the early diagnostic steps is a blood test to measure levels of frataxin, a protein that is essential for cells to produce energy properly. In people with Friedreich’s ataxia, frataxin levels are very low. However, a normal blood test does not always rule out FA, because some people may still have the condition even if initial tests appear normal.^[20]

Genetic Testing

The only way to confirm a diagnosis of Friedreich’s ataxia with certainty is through genetic testing. This test looks at the FXN gene, which carries the instructions for making frataxin. In most people with FA, there is an abnormal pattern in the DNA of this gene, called a GAA triplet repeat. This pattern repeats hundreds of times more than it should, which disrupts the normal production of frataxin.^[1]

Genetic testing is done using a blood sample, and it can identify whether someone has two changed copies of the FXN gene—one from each biological parent. Friedreich’s ataxia is inherited in what doctors call an autosomal recessive pattern, meaning that both parents typically carry one changed copy of the gene but do not show symptoms themselves.^[3]

Because genetic testing provides a definitive answer, it is considered the gold standard for diagnosing FA. It can also help distinguish FA from other types of ataxia, which are conditions that cause similar movement and balance problems but have different causes.^[4]

Imaging Studies

In some cases, doctors may order imaging tests to help understand what is happening in the brain and spinal cord. A magnetic resonance imaging scan, or MRI, is a type of imaging that uses magnets and radio waves to create detailed pictures of the inside of the body. An MRI can show whether there are changes in the cerebellum, the part of the brain that helps with balance and movement. It can also reveal thinning of the spinal cord, which is common in people with FA.^[1]

However, it is important to know that an MRI alone cannot diagnose Friedreich’s ataxia. Some people with FA may have a normal-looking MRI, especially in the early stages of the disease. That is why imaging is used together with other tests, not as a replacement for genetic testing.^[4]

Nerve Conduction Studies and Electromyography

To understand how well the nerves and muscles are working, doctors may perform tests called nerve conduction studies and electromyography, often shortened to NCV and EMG. These tests measure the electrical activity of nerves and muscles. In people with Friedreich’s ataxia, the peripheral nerves—those that connect the spinal cord to the rest of the body—are often damaged, and these tests can detect that damage.^[20]

During a nerve conduction study, small electrodes are placed on the skin, and a mild electrical pulse is used to stimulate the nerves. The test measures how quickly and effectively the nerves send signals. Electromyography involves inserting a thin needle into a muscle to record its electrical activity. While these tests can be uncomfortable, they provide valuable information about the extent of nerve damage.^[4]

Heart Evaluation

Because Friedreich’s ataxia can affect the heart, doctors often perform tests to check heart function as part of the diagnostic process. An electrocardiogram, or ECG, is a simple test that records the electrical activity of the heart. It can detect irregular heart rhythms, which are common in people with FA.^[3]

Another test, called an echocardiogram, uses sound waves to create a moving picture of the heart. This test can show whether the heart muscle has thickened, a condition called cardiomyopathy. Heart problems are a leading cause of serious complications in FA, so regular heart monitoring is an important part of managing the condition.^[1]

Other Tests

Depending on symptoms, doctors may also order tests to check for other conditions that can occur with FA. For example, blood sugar tests can detect diabetes, which affects about 30 percent of people with Friedreich’s ataxia. Vision and hearing tests may also be performed, as some people with FA experience loss of sight or hearing over time.^[3]

Diagnostic Testing for Clinical Trial Qualification

If you or a loved one is considering participating in a clinical trial for Friedreich’s ataxia, additional testing may be required. Clinical trials are research studies that test new treatments or therapies, and they have specific criteria to determine who can take part. These criteria help researchers ensure that the trial is safe and that the results are meaningful.^[9]

Genetic Confirmation

Most clinical trials for FA require participants to have genetically confirmed Friedreich’s ataxia. This means that genetic testing must show the presence of the GAA triplet repeat in the FXN gene. Trials may also specify how many repeats are present, as this can affect the severity of the disease and how a person might respond to treatment.^[9]

Assessment of Disease Severity

To qualify for a clinical trial, participants often need to undergo tests that measure the severity of their symptoms. One common tool is the modified Friedreich’s Ataxia Rating Scale, or mFARS. This scale evaluates various aspects of movement and function, such as walking ability, hand coordination, speech, and posture. A specific range of mFARS scores may be required for enrollment, ensuring that participants are at a stage of the disease where the treatment being tested is most likely to have an effect.^[11]

For example, the clinical trial that led to the approval of omaveloxolone, the first drug approved for FA, required participants to have baseline mFARS scores between 20 and 80. This range captured people who had moderate impairment but were not yet in the most advanced stages of the disease.^[11]

Heart Function Tests

Because heart complications are common in Friedreich’s ataxia and can be serious, many clinical trials require participants to undergo heart function tests before enrolling. An echocardiogram is often used to check for cardiomyopathy or other heart abnormalities. Some trials may exclude participants with severe heart disease, while others may focus specifically on testing treatments for heart problems related to FA.^[9]

Blood Tests and Kidney Function

Clinical trials typically require blood tests to check overall health and to ensure that the liver and kidneys are functioning properly. These tests help determine whether a person can safely take the experimental treatment being studied. Some medications may not be suitable for people with certain blood abnormalities or poor kidney or liver function.^[9]

Cognitive and Neurological Assessments

Some clinical trials may include tests of thinking, memory, and problem-solving abilities. While Friedreich’s ataxia primarily affects movement and coordination, some people may experience slower information processing or other cognitive changes. Assessing these areas helps researchers understand the full impact of the disease and how a treatment might affect different aspects of health.^[9]

Quality of Life Questionnaires

Participants in clinical trials may also be asked to complete questionnaires about their quality of life. These questionnaires ask about daily activities, emotional well-being, and how symptoms affect everyday tasks. This information is valuable because it helps researchers understand not only whether a treatment works, but also whether it makes a meaningful difference in people’s lives.^[11]

Age and Other Eligibility Criteria

Clinical trials for Friedreich’s ataxia often have age requirements. For example, some trials may only accept participants who are 16 years or older, while others may include younger children or focus on adults. Other eligibility criteria might include whether a person is already using certain medications, whether they have other medical conditions, and how long they have had symptoms.^[12]

Each clinical trial has its own specific set of criteria, which are designed to test the treatment in a group of people who are most likely to benefit. If you are interested in participating in a clinical trial, your doctor can help you understand which trials you may qualify for and what testing will be needed.^[9]