What are other Names for this Condition? (Also known as/Synonyms)

• Familial, Genetic, or Inherited Prion Disease
• fCJD (Familial Creutzfeldt-Jakob Disease)
• Gerstmann Straussler Scheinker (GSS) Disease

What is Familial Creutzfeldt-Jakob Disease? (Definition/Background Information)

• Familial Creutzfeldt-Jakob Disease (fCJD) is a rare, progressive degenerative disease of the brain that occurs following the inheritance of a mutated gene for a specific protein that acts in the brain, called prions
• Prions are infectious pathogens, but are very different from other pathogens, such as bacteria, viruses, and fungi. They are unusual, because they lack both DNA and RNA molecules. Instead, prions are normal cellular proteins that take on an abnormal configuration
• Prions are able to multiply by converting similar normal proteins in the brain into infectious abnormal forms, ultimately leading to the destruction of brain tissue. As a result, individuals with CJD develop dementia, involuntary muscle jerks (myoclonus), loss of motor coordination, and psychiatric symptoms
• Familial Creutzfeldt-Jakob Disease is inherited in an autosomal dominant manner from generation to generation, which means that if one parent has the mutated gene, their child has a 50% chance of developing CJD
• There is no cure for fCJD; the treatment provided is often symptomatic. The prognosis of Creutzfeldt-Jakob Disease is usually poor

Creutzfeldt-Jakob Disease is also known as subacute or transmissible spongiform encephalopathy. Several types of CJD exist. All types involve an abnormal form of a naturally-occurring protein in the central nervous system.

• Sporadic Creutzfeldt-Jakob Disease (sCJD) is the most common form of the disorder and accounts for approximately 85% of all cases
• Familial Creutzfeldt-Jakob Disease (fCJD) is an inherited form caused by genetic mutations on chromosome 20
• Iatrogenic Creutzfeldt-Jakob Disease (iCJD) is an unintended consequence of medical therapy
• New Variant (or Variant) Creutzfeldt-Jakob Disease (nvCJD or vCJD) is due to the consumption of contaminated beef from cattle affected by a similar disease, called bovine spongiform encephalopathy (BSE)

Who gets Familial Creutzfeldt-Jakob Disease? (Age and Sex Distribution)

• Familial Creutzfeldt-Jakob Disease is found worldwide. They form about 15% of all CJD cases, which is an incidence of approximately 1 case per 1,000,000 people
• fCJD can affect individuals of any age, but most individuals are typically 30-60 years old when onset occurs
• Both males and females are equally affected and no particular preference is observed
• Familial Creutzfeldt-Jakob Disease does not show higher prevalence in any specific racial, ethnic, or geographical group

What are the Risk Factors for Familial Creutzfeldt-Jakob Disease? (Predisposing Factors)

There are currently no controllable risk factors for developing Familial Creutzfeldt-Jakob Disease due to the genetic nature.

• Having a parent with this genetic disorder is the key risk factor for Familial Creutzfeldt-Jakob Disease. Thus, a positive family history increases one’s risk. If one parent has fCJD, then there is a 50% chance that their child will inherit the condition
• It is important to note that all forms of Creutzfeldt-Jakob Disease are not contagious via air or casual contact. Having close interactions with or living with an individual who has CJD does not increase one’s risk for developing CJD
• However, contact with spinal cord fluid or brain tissue from an infected individual can result in the development of Creutzfeldt-Jakob Disease

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Familial Creutzfeldt-Jakob Disease? (Etiology)

• Familial Creutzfeldt-Jakob Disease is an inherited genetic disorder
• A genetic mutation in the genes for the prion protein on chromosome 20 is the cause of Familial Creutzfeldt-Jakob Disease. The disease is potentially passed down from an individual with fCJD, to his or her children, via an autosomal dominant pattern

Autosomal dominant: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly functioning gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition or pass it on to their offspring.

What are the Signs and Symptoms of Familial Creutzfeldt-Jakob Disease?

The signs and symptoms of Familial Creutzfeldt-Jakob Disease may include:

• Some individuals may initially experience fatigue, sleep disturbances, hallucinations, weight loss, headaches, and pain
• The initial symptoms in most individuals are mainly cognitive and include memory loss, confusion, and impaired judgment
• Some have vision, speech, or gait disturbances
• Other possible symptoms include rigidity, uncontrollable limb movements, poor coordination, and seizures
• Sudden, loud noises or bright light may trigger myoclonus (involuntary twitching of muscles). This may also occur during sleep
• Depression and sensory disturbances are common in nvCJD
• In all cases, the symptoms progress to profound dementia

How is Familial Creutzfeldt-Jakob Disease Diagnosed?

A diagnosis of Familial Creutzfeldt-Jakob Disease may involve:

• Complete medical history and a thorough physical examination; a positive family history may help diagnose CJD in a minority of cases
• Symptoms of dementia, myoclonus, and an abnormal EEG, in a middle-aged individual can suggest a diagnosis of Creutzfeldt-Jakob Disease
• For Familial CJD, a blood test can be taken, which helps determine if there is a mutation in the protein coding gene for prions. If one individual is positive for a mutation of this type, it raises awareness for siblings, children, or other blood relatives of the possibility of having the mutation for fCJD as well
• Brain MRI may be helpful in diagnosing sCJD
• CJD may be confirmed by brain tissue biopsy and assays that detect abnormal prion proteins. If a biopsy is negative, the diagnosis of CJD may not be ruled out, because prion proteins may be absent from a small tissue sample. In such cases, a final diagnosis may not be made until autopsy

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Familial Creutzfeldt-Jakob Disease?

The complications of Familial CJD may include:

• Individuals frequently develop pneumonia during the later stages of the disease, and this is often fatal
• Severe dementia may cause significant stress and social issues

How is Familial Creutzfeldt-Jakob Disease Treated?

There are currently no effective treatments available for Familial Creutzfeldt-Jakob Disease.

• Quinacrine has shown to slow the rate of decline in some patients
• The affected individuals receive supportive care and may be given medications to control myoclonus and pain, if present
• Treatments in development for CJD include the use of antibodies against prions and several drugs with potential therapeutic efficacy

How can Familial Creutzfeldt-Jakob Disease be Prevented?

• Currently, there are no specific methods or guidelines to prevent Familial Creutzfeldt-Jakob Disease, since it is a genetic condition
• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders such as Familial Creutzfeldt-Jakob Disease

What is the Prognosis for Familial Creutzfeldt-Jakob Disease? (Outcomes/Resolutions)

• There is a highly variable incubation period in Creutzfeldt-Jakob Disease, following the transmission of prions. Symptoms have been observed in as few as 1-2 years, or after as many as 30 years, especially in the case of nvCJD
• Individuals diagnosed with CJD may live 3 months to 5 years following onset of symptoms. However with CJD, in a majority of cases, death usually results in less than 1 year
• 5-10% of the patients survive more than 2 years.  Patients with fCJD tend to live longer than those with sCJD

Additional and Relevant Useful Information for Familial Creutzfeldt-Jakob Disease:

There are voluntary organizations and support groups that provide counsel, help, and understanding to the individuals and families affected by Creutzfeldt-Jakob Disease.