Dear Relative,

            Many of you are aware that several family members have died from a rare neurodegenerative disease known as Creutzfeldt-Jakob Disease (CJD). Recently, after genetic testing,  another family member has been diagnosed the familial form of  Creutzfeldt-Jakob Disease.  CJD is a disease that is caused by an abnormal protein, called a prion, which builds up in the brain.   Like the other forms of CJD, familial CJD is characterized by dementia (mental decline with symptoms such as memory loss) and neurological problems such as unsteadiness.  Familial CJD typically begins with symptoms of depression, memory lapses, or unsteadiness and lack of coordination and rapidly progresses into dementia.  Other symptoms include sudden jerky movements, rigid limbs, maybe blindness and incontinence. Eventually the person loses the ability to move or speak, and will need full-time nursing care. In our family, people have developed this disease between the ages of 40 and 65, but at least one member of the family died at an older age from a different cause. The disease can progress quickly over a few months or more slowly resulting in death after a few years.

Familial CJD is caused by a mutation (alteration) in the PRNP gene that codes for the prion protein. All of the mutations are inherited in an autosomal dominant pattern, meaning, if one parent carries the mutation, there is a 50-50 chance for each child to inherit the mutation. Since the onset of CJD is typically later in life, after most people have usually had their children, the gene has persisted in the population.

            Mutations in the PRNP gene can now be detected via a blood test. At risk family members who do not have symptoms, therefore, can opt to find out whether they carry the mutation. The genetic test will indicate that an individual carries or does not carry the gene, but will not tell when or how symptoms will develop. Obviously, undergoing PRNP gene testing is a very personal matter and should not be done without the full consent of the person involved, and full pre- and post-test genetic counseling. The results will have an impact on other family members and they should also be involved in discussions.

           
             The doctors and genetic counselors at the Taub Institute at Columbia University have been involved in the diagnosis and care of several family members. If you have any questions regarding the genetics of this disease or your own risk, please call the genetic counselor, Jill Goldman at 212-305-7382.

            Sincerely,
           Eric Bjorklund