Friedreich’s Ataxia

Friedreich’s ataxia (also called FA or FRDA) is a rare inherited disease that causes nervous system damage and movement problems. It usually begins in childhood and leads to impaired muscle coordination (ataxia) that worsens over time. The disorder is named after Nicholaus Friedreich, a German doctor who first described the condition in the 1860s.

In Friedreich’s ataxia the spinal cord and peripheral nerves degenerate, becoming thinner. The cerebellum, part of the brain that coordinates balance and movement, also degenerates to a lesser extent. This damage results in awkward, unsteady movements and impaired sensory functions. The disorder also causes problems in the heart and spine, and some people with the condition develop diabetes. The disorder does not affect thinking and reasoning abilities (cognitive functions).

Friedreich’s ataxia is caused by a defect (mutation) in a gene labeled FXN. The disorder is recessive, meaning it occurs only in someone who inherits two defective copies of the gene, one from each parent. Although rare, Friedreich’s ataxia is the most common form of hereditary ataxia, affecting about 1 in every 50,000 people in the United States. Both male and female children can inherit the disorder.

What are the signs and symptoms?
Symptoms typically begin between the ages of 5 and 15 years, although they sometimes appear in adulthood and on rare occasions as late as age 75. The first symptom to appear is usually gait ataxia, or difficulty walking. The ataxia gradually worsens and slowly spreads to the arms and the trunk. There is often loss of sensation in the extremities, which may spread to other parts of the body. Other features include loss of tendon reflexes, especially in the knees and ankles. Most people with Friedreich’s ataxia develop scoliosis (a curving of the spine to one side), which often requires surgical intervention for treatment.

Dysarthria (slowness and slurring of speech) develops and can get progressively worse. Many individuals with later stages of Friedreich’s ataxia develop hearing and vision loss.

Other symptoms that may occur include chest pain, shortness of breath, and heart palpitations. These symptoms are the result of various forms of heart disease that often accompany Friedreich’s ataxia, such as hypertrophic cardiomyopathy (enlargement of the heart), myocardial fibrosis (formation of fiber-like material in the muscles of the heart), and cardiac failure. Heart rhythm abnormalities such as tachycardia (fast heart rate) and heart block (impaired conduction of cardiac impulses within the heart) are also common.

About 20 percent of people with Friedreich’s ataxia develop carbohydrate intolerance and 10 percent develop diabetes. Most individuals with Friedreich’s ataxia tire very easily and find that they require more rest and take a longer time to recover from common illnesses such as colds and flu.

The rate of progression varies from person to person. Generally, within 10 to 20 years after the appearance of the first symptoms, the person is confined to a wheelchair, and in later stages of the disease individuals may become completely incapacitated.

Friedreich’s ataxia can shorten life expectancy, and heart disease is the most common cause of death. However, some people with less severe features of Friedreich’s ataxia live into their sixties, seventies, or older.

How is Friedreich’s ataxia diagnosed?
A diagnosis of Friedreich’s ataxia requires a careful clinical examination, which includes a medical history and a thorough physical exam, in particular looking for balance difficulty, loss of proprioception (joint sensation), absence of reflexes, and signs of neurological problems. Genetic testing now provides a conclusive diagnosis. Other tests that may aid in the diagnosis or management of the disorder include:

  • electromyogram (EMG), which measures the electrical activity of muscle cells,
  • nerve conduction studies, which measure the speed with which nerves transmit impulses,
  • electrocardiogram (ECG), which gives a graphic presentation of the electrical activity or beat pattern of the heart,
  • echocardiogram, which records the position and motion of the heart muscle,
  • blood tests to check for elevated glucose levels and vitamin E levels, and
  • magnetic resonance imaging (MRI) or computed tomography (CT) scans, tests which provide brain and spinal cord images that are useful for ruling out other neurological conditions.

How is Friedreich’s ataxia inherited?
Friedreich’s ataxia is an autosomal recessive disease, meaning individuals only develop symptoms if they inherit two copies of the defective FXN gene, one from their father and one from their mother. A person who has only one abnormal copy of the gene is called a carrier. A carrier will not develop the disease but could pass the gene mutation on to his or her children. If both parents are carriers, their children will have a 1 in 4 chance of having the disease and a 1 in 2 chance of inheriting one abnormal gene that they, in turn, could pass on to their children. About one in 90 Americans of European ancestry carries an abnormal FXN gene.

In 1996, an international research team identified the Friedreich’s ataxia gene on chromosome 9. The FXN gene codes for production of a protein called “frataxin.” In the normal version of the gene, a sequence of DNA (labeled “GAA”) is repeated between 7 and 22 times. In the defective FXN gene, the repeat occurs over and over again—hundreds, even up to a thousand times.

This abnormal pattern, called a triplet repeat expansion, has been implicated as the cause of several dominantly inherited diseases, but Friedreich’s ataxia is the only known recessive genetic disorder caused by the problem. Almost all people with Friedreich’s ataxia have two copies of this mutant form of FXN, but it is not found in all cases of the disease. About two percent of affected individuals have other defects in the FXN gene that are responsible for causing the disease.

The triplet repeat expansion greatly disrupts the normal production of frataxin. Frataxin is found in the energy-producing parts of the cell called mitochondria. Research suggests that without a normal level of frataxin, certain cells in the body (especially peripheral nerve, spinal cord, brain and heart muscle cells) cannot effectively produce energy and have been hypothesized to have a buildup of toxic byproducts leading to what is called “oxidative stress.” It also may lead to increased levels of iron in the mitochondria. When the excess iron reacts with oxygen, free radicals can be produced. Although free radicals are essential molecules in the body’s metabolism, they can also destroy cells and harm the body. Research continues on this subject (see section on “What research is being done?”).

Can Friedreich’s ataxia be cured or treated?
As with many degenerative diseases of the nervous system, there is currently no cure or effective treatment for Friedreich’s ataxia. However, many of the symptoms and accompanying complications can be treated to help individuals maintain optimal functioning as long as possible. Doctors can prescribe treatments for diabetes, if present; some of the heart problems can be treated with medication as well. Orthopedic problems such as foot deformities and scoliosis can be corrected with braces or surgery. Physical therapy may prolong use of the arms and legs. Advances in understanding the genetics of Friedreich’s ataxia are leading to breakthroughs in treatment. Research has moved forward to the point where clinical trials of proposed treatments are presently occurring for Friedreich’s ataxia.

What services are useful to Friedreich’s ataxia patients and their families?
Genetic testing is essential for proper clinical diagnosis, and can aid in prenatal diagnosis and determining a person’s carrier status. Genetic counselors can help explain how Friedreich’s ataxia is inherited. Psychological counseling and support groups for people with genetic diseases may also help affected individuals and their families cope with the disease.

A primary care physician can screen people for complications such as heart disease, diabetes and scoliosis, and can refer individuals to specialists such as cardiologists, physical therapists, and speech therapists to help deal with some of the other associated problems.

Support and information for families is also available through a number of private organizations. These groups can offer ways to network and communicate with others affected by Friedreich’s ataxia. They can also provide access to patient registries, clinical trials information, and other useful resources.

What research is being done?
Within the Federal government the National Institute of Neurological Disorders and Stroke (NINDS), a component of the National Institutes of Health (NIH), has primary responsibility for sponsoring research on neurological disorders. As part of this mission, the NINDS conducts research on Friedreich’s ataxia and other forms of inherited ataxias at its facilities at the NIH and supports additional studies at medical centers throughout the United States. Several nonprofit organizations also provide substantial support research (see the section on “Where can I get more information?”).

Researchers are optimistic that they have begun to understand the causes of the disease, and work has begun to develop effective treatments and prevention strategies for Friedreich’s ataxia. Scientists have been able to create various models of the disease in yeast and mice which have facilitated understanding the cause of the disease and are now being used for drug discovery and the development of novel treatments.

Studies have revealed that frataxin is an important mitochondrial protein for proper function of several organs. Yet in people with the disease, the amount of frataxin in affected cells is severely reduced. It is believed that the loss of frataxin makes the nervous system, heart, and pancreas particularly susceptible to damage from free radicals (produced when the excess iron reacts with oxygen). Once certain cells in these tissues are destroyed by free radicals they cannot be replaced. Nerve and muscle cells also have metabolic needs that may make them particularly vulnerable to this damage. Free radicals have been implicated in other degenerative diseases such as Parkinson’s and Alzheimer’s diseases.

Based upon this information, scientists and physicians have tried to reduce the levels of free radicals, also called oxidants, using treatment with “antioxidants.” Initial clinical studies in Europe suggested that antioxidants like coenzyme Q10, vitamin E, and idebenone may offer individuals some limited benefit. However, recent clinical trials in the United States and Europe have not revealed effectiveness of idebenone in people with Friedreich’s ataxia, but more powerful modified forms of this agent and other antioxidants are in trials at this time. There is also a clinical trial to examine the efficacy of selectively removing excess iron from the mitochondria.

Scientists also are exploring ways to increase frataxin levels through drug treatments, genetic engineering and protein delivery systems. Several compounds that are directed at increasing levels of frataxin may be brought to clinical trials in the near future. To check for current trials, visit http://www.clinicaltrials.gov. Additional information is available from the groups listed in the following section.

Armed with what they currently know about frataxin and Friedreich’s ataxia, scientists are working to better define fraxatin’s role, clarify how defects in iron metabolism may be involved in the disease process, and explore new therapeutic approaches for therapy.

Service dogs

Service dogs can build your independence by boosting your mobility. These four-legged friends pull wheelchairs, function as a mobile cane for balance, and even perform many of the daily tasks you may have difficulty with.

While these “working dogs” are trained to retrieve dropped items, pull clothing on and off, and bring medication, their canine capabilities also prove to be essential in an emergency. For all of the reasons your furry friend is important to your daily routine, it’s equally important to ensure their safety during travel. Properly securing your service animal correctly in your vehicle can be a matter of life and death for both of you.

Just as you would secure your wheelchair with straps and other devices, you should secure your service animal properly and comfortably in your vehicle, as well. Be sure the car is properly ventilated and that crates or units are secured.

As a service dog usually stays by the owner’s side, a belt usually proves as the best option in securing your dog in the vehicle to guarantee his/her safety. Help your hound out with a body harness specifically made for canine car travel. Service vests can even be custom-made to better suit your animal and your vehicle.

Some dogs may get uncomfortable not being able to look out of the window and see where they are going, especially small dogs. The Snoozer Lookout helps satisfy your pooch’s curiosity and need to see. The Snoozer Lookout is a seat that allows your pet to sit higher while staying safely strapped in.

It goes without saying that properly securing your service animal not only keeps them safe from harm on the roadways, but also makes for a comfortable ride along with you.

Accessible Holiday Parties

Plan ahead by finding out information about your guests.

  • Ask if anyone has a special diet or food allergy to consider
  • Find out if anyone is bringing a service animal – your Fluffy may not appreciate Fido, so you may want to take your pets into a separate area of your home
  • Decide what area of the house could be a private place – some people may need to take medication, change feeding tubes or have other personal needs

Food accessibility can be determined by thinking about food shape, size, consistency, and packaging.

  • Large and floppy sandwiches with loose ingredients may be difficult to hold for those with limited dexterity
  • Try to limit the use of wet ingredients in sandwiches, like tomatoes, because it makes them soggy and hard to hold
  • Smaller items are easier to eat and pick up
  • Limit the amount of cutting that foods require
  • Serve foods that stay on a fork – rice, small vegetables and long spaghetti noodles are more difficult than tortellini or rigatoni
  • Soup is not very accessible
  • Have a variety of differently sized and shaped cutlery
  • Straws, cups with lids and beverages in both cans and bottles provide beverage accessibility
  • Packaging should be easy to open and re-sealable to enable small eaters to save food for later

Conduct an accessibility review of your home. You can’t change everything, such as the foundation of your home, but you can make some simple changes to your home to ensure that people in wheelchairs have better access to things they need:

  • Consider the height of your table – can a wheelchair fit comfortably? If not, consider swapping out your regular dinner table for something taller or shorter
  • Remove barriers that make navigating your house difficult – take out extra coffee tables, lamps, chairs, throw rugs and items that sit on the floor
  • Ensure adequate lighting for persons with visual impairments
  • Keep music low as laughter, noise, talking, music, lights and excitement may already cause over stimulation

Batten Disease

What is Batten Disease?
Batten disease is named after the British pediatrician who first described it in 1903. Also known as Spielmeyer-Vogt-Sjogren-Batten disease, it is the most common form of a group of disorders called Neuronal Ceroid Lipofuscinoses (or NCL).

Although Batten disease is usually regarded as the Juvenile form of NCL, it has now become the term to encompass all forms of NCL.

The forms of NCL are classified by age of onset and have the same basic cause, progression and outcome but are all genetically different, meaning each is the result of a different gene. Over time, affected children suffer mental impairment, worsening seizures, and progressive loss of sight and motor skills. Eventually, children with Batten disease/NCL become blind, bedridden and unable to communicate, and, presently, it is always fatal.

Batten disease is not contagious or, at this time, preventable.

The History of Neuronal Ceroid Lipofuscinosis
The first probable instances of this condition were reported in 1826 in a Norwegian medical journal by Dr. Christian Stengel, who described three affected siblings in a small mining community in Norway. Although no pathological studies were performed on these children, the clinical descriptions are so succinct that the diagnosis of the Spielmeyer-Sjogren (juvenile) type is fully justified. More fundamental observations were reported by F.E. Batten in 1903, and by Vogt in 1905, who performed extensive clinicopathological studies on several families. Retrospectively, these papers disclose that the authors grouped together different types of the disease.

Furthermore Batten, at least for some time, insisted that the condition he described was distinctly different from Tay-Sachs Disease, the prototype of a neuronal lysosomal disorder now identified as GM2-Gangliosidosis type A. Around the same time, Spielmeyer reported detailed studies on three siblings, suffering from the Spielmeyer-Sjogren (juvenile) type, which led him to the very firm statement that this malady is not related to Tay-Sachs Disease. Subsequently, however, the pathomorphological studies of Schaffer made these authors change their minds to the extent that they reclassified their respective observations as variants of Tay-Sachs Disease, which caused confusion for about 50 years.

In 1913-14, M. Bielschowsky delineated the Late Infantile form of NCL. However, all forms were still thought to belong in the group of “familial amaurotic idiocies,” of which Tay-Sachs was the prototype.

In 1931, the Swedish psychiatrist and geneticist, Torben Sjogren, presented 115 cases with extensive clinical and genetic documentation and came to the conclusion that the disease which we now call the Spielmeyer-Sjogren (juvenile) type is genetically separate from Tay-Sachs.

Departing from the careful pathomorphological observations of Spielmeyer, Hurst, Sjovall and Ericsson, Zeman and Alpert made a determined effort to document the previously suggested pigmentary nature of the neuronal deposits in certain types of storage disorders. Simultaneously, Terry, Korey and Svennerholm demonstrated a specific ultrastructure and biochemistry for Tay-Sachs Disease, and these developments led to the distinct identification, and separation, of the NCLs from Tay-Sachs Disease by Zeman and Donahue. At that time, it was proposed that the Late Infantile (Jansky-Bielschowsky), the Juvenile (Spielmeyer-Vogt), and the adult forms (Kufs) were quite different from Tay-Sachs Disease with respect to chemical pathology and ultrastructure, and also different from other forms of sphingolipidoses. Subsequently, it was shown by Santavuori and Haltia that an Infantile form of NCL exists, which Zeman and Dyken had included with the Jansky-Bielschowsky type.

What are the forms of NCL/Batten Disease?
There are four main types of NCL, including two forms that begin earlier in childhood and a very rare form that strikes adults. The symptoms are similar but the forms become apparent at different ages and progress at different rates.

  • Infantile NCL (Santavuori-Haltia disease) begins between about 6 months and 2 years of age and progresses rapidly. Affected children fail to thrive and have abnormally small heads (microcephaly). Also typical are short, sharp muscle contractions called myoclonic jerks. Initial signs of this disorder include delayed psychomotor development with progressive deterioration, other motor disorders, or seizures. The Infantile form has the most rapid progression and children live into their mid-childhood years.
  • Late Infantile NCL (Jansky-Bielschowsky disease) begins between ages 2 and 4. The typical early signs are loss of muscle coordination (ataxia) and seizures along with progressive mental deterioration. This form progresses rapidly and ends in death between ages 8 and 12.
  • Juvenile NCL (Batten disease) begins between the ages of 5 and 8. The typical early signs are progressive vision loss, seizures, ataxia or clumsiness. This form progresses less rapidly and ends in death in the late teens or early 20s, although some may live into their 30s.
  • Adult NCL (Kufs disease or Parry disease) generally begins before the age of 40, causes milder symptoms that progress slowly, and does not cause blindness. Although age of death is variable among affected individuals, this form does shorten life expectancy.

There are six additional diseases included in the Batten disease/NCL group:

  • Finnish Late Infantile – identified in Finland
  • Variant Late Infantile – identified in Costa Rica, South America, Portugal and other nations
  • Turkish Late Infantile – identified in Turkey
  • Northern Epilepsy/ERMP – Epilepsy with Mental Retardation – identified in Finland
  • Variant Juvenile – identified in Germany and USA
  • Congenital/CTSD – identified in Europe

A more precise chart of the forms of Batten disease is below:

Chart: Forms of Batten Disease
Form Initials  Gene  Age of Onset 
Infantile INCL CLN1 6 mos. — 2 yrs.
Late Infantile LINCL CLN2 2 — 4 yrs.
Juvenile JNCL CLN3 5 — 7 yrs.
Adult ANCL CLN4 25 — 40 yrs.
Finnish Late Infantile fLINCL CLN5 2 — 4 yrs.
Variant Late Infantile vLINCL CLN6 3 — 5 yrs.
Turkish Late Infantile tLINCL CLN7 2 — 4 yrs.
Northern Epilepsy EPMR CLN8 5 — 10 yrs.
Variant Juvenile vJNCL CLN9 5 — 7 yrs.
Congenital CTSD CLN10 Birth — 2 yrs.

How many people have these disorders?
Batten disease/NCL is relatively rare, occurring in an estimated 2 to 4 of every 100,000 births in the United States, but no one really knows how many affected children there may be in North America or anywhere else in the world. The diseases have been identified worldwide. Although NCLs are classified as rare diseases, they often strike more than one person in families that carry the defective gene.

How are NCLs inherited?
Childhood NCLs are autosomal recessive disorders; that is, they occur only when a child inherits two copies of the defective gene, one from each parent. When both parents carry one defective gene, each of their children faces a one in four chance of developing NCL. At the same time, each child also faces a one in two chance of inheriting just one copy of the defective gene. Individuals who have only one defective gene are known as carriers, meaning they do not develop the disease, but they can pass the gene on to their own children.

Adult NCL may be inherited as an autosomal recessive (Kufs) or, less often, as an autosomal dominant (Parry) disorder. In autosomal dominant inheritance, all people who inherit a single copy of the disease gene develop the disease. As a result, there are no unaffected carriers of the gene.

What causes these diseases?
Symptoms of Batten disease/NCLs are linked to a buildup of substances called lipopigments in the body’s tissues. These lipopigments are made up of fats and proteins. Their name comes from the technical word lipo, which is short for “lipid” or fat, and from the term pigment, used because they take on a greenish-yellow color when viewed under an ultraviolet light microscope.

The lipopigments build up in cells of the brain and the eye, as well as in skin, muscle, and many other tissues. Inside the cells, these pigments form deposits with distinctive shapes that can be seen under an electron microscope. Some look like half-moons (or comas) and are called curvilinear bodies; others look like fingerprints and are called fingerprint inclusion bodies; and still others resemble gravel (or sand) and are called granual osmophilic deposits (GRODS).

Batten Disease - What causes these diseases?

These deposits are what doctors look for when they examine a skin sample to diagnose Batten disease. The diseases cause the death of neurons (specific cells found in the brain, retina and central nervous system). The reason for neuron death is still not known.

How are these disorders diagnosed?
Because vision loss is often an early sign, Batten disease/NCL may first be suspected during an eye exam. An eye doctor can detect a loss of cells within the eye that occurs in the three childhood forms of Batten disease/NCL. However, because such cell loss occurs in other eye diseases, the disorder cannot be diagnosed by this sign alone.

Often an eye specialist/ophthalmologist or other physician who suspects Batten disease/NCL may refer the child to a neurologist, a doctor who specializes in diseases of the brain and nervous system. In order to diagnose Batten disease/NCL, the neurologist needs the patient’s medical history and information from various laboratory tests. Below are pictures of the retina showing the telltale signs of Batten disease.

Batten Disease and Ophthalmology

Batten Disease-How are these disorders diagnosed?

In the Fundus (the interior surface of the eye), the pigmentary changes in the macula are initially slight, and so it is easy to miss them, especially when no pupil dilation is applied and the fundus is not examined carefully. Fluorescent angiography demonstrates the pigmentary changes more clearly (Prammer, et al., 1978- ); sometimes fluorescence can be observed, leaking out of the retinal vessels. The density of the fine particuled pigmentations is slight around the macula and increases towards the periphery (Gottinger, et al., 1971- ). Dyken (1976) also mentions peripheral depigmentation. The pigment epithelium frequently has a granular “pepper and salt” appearance (see Fig. 1); sometimes there is a characteristic “bull’s eye” maculopathy (see Fig. 2, Fig. 3). The papilla becomes paler and the retinal arterioles seem more obviously constricted and extended (Fig. 4, Fig. 5). The peripheral retina varies in appearance, from normal to showing pigment-epithelial (pigmented cell layer just outside the retina) abnormalities (Spalton, et al., 1980- ). Later, peripheral pigment is often seen in the form of bone corpuscular pigment (see Fig. 6). Cataracts develop later in the course of the disease.

Diagnostic tests used for Batten disease/NCLs include:
Skin or Tissue Sampling: The doctor examines a small piece of tissue under an electron microscope. The powerful magnification of the microscope helps the doctor spot typical NCL deposits. These deposits are found in many different tissues, including skin, muscle, conjunctiva, rectal and others. Blood can also be used. See inclusion body pictures above.

Electroencephalogram or EEG: An EEG uses special patches placed on the scalp to record electrical currents inside the brain. This helps doctors see telltale patterns in the brain’s electrical activity that suggest a patient has seizures.

Electrical Studies of the Eyes: These tests, which include visual-evoked responses (VER) and electro-retinagrams (ERG), can detect various eye problems common in childhood Batten disease/NCLs.

Brain Scans: Imaging can help doctors look for changes in the brain’s appearance. The most commonly used imaging technique is computed tomography (CT), which uses x-rays and a computer to create a sophisticated picture of the brain’s tissues and structures. A CT scan may reveal brain areas that are decaying in NCL patients. A second imaging technique that is increasingly common is magnetic resonance imaging, or MRI. MRI uses a combination of magnetic fields and radio waves, instead of radiation, to create a picture of the brain.

Enzyme Assay: A recent development in the diagnosis of Batten disease/NCL is the use of enzyme assays that look for specific missing lysosomal enzymes for Infantile and Late Infantile only. This is a quick and easy diagnostic test.

Genetic/DNA Testing: Each “form” of Batten disease is the result of a different gene. Genes for eight of the ten forms have been identified. Testing for these is available for diagnosis as well as carrier and prenatal status.

Is there any treatment?
As yet, no specific treatment is known that can halt or reverse the symptoms of Batten disease/NCL. However, seizures can be reduced or controlled with anticonvulsant drugs, and other medical problems can be treated appropriately as they arise. At the same time, physical and occupational therapy may help patients retain function as long as possible.

BDSRA helps scientists by fostering awareness, promoting more research, providing samples and information, and by funding research that is directed towards understanding all forms of Batten disease and development of therapies.

Support and encouragement can help children and families cope with the profound disability and losses caused by NCLs. The Batten Disease Support and Research Association enables affected children, adults and families to share common concerns and experiences.

Meanwhile, scientists pursue medical research that will someday yield an effective treatment.