Physicians diagnose SCA3 with recognizing the symptoms of the disease by performing a neurological examination which includes testing certain sensory-motor skills. A family history is also documented along with a family pedigree (or family tree). Detailed questions are asked about family members who show, or showed, symptoms of the disease. However, a definitive diagnosis of SCA3 can only be made with a DNA test. Blood samples are drawn and are then sent to a laboratory to be analyzed to detect the abnormal gene by determin-ing the number of CAG repeats. A person with SCA3 would have 60-80 repeats. Whereas, a person with a count of 12-37 would not be affected. The decision to have a genetic test is a personal one and should not be taken lightly. A genetic counselor can help explore the benefits and downsides of getting tested as well as help in understanding the implications of the test results. When deciding whether or not to test, plan to talk with a genetic counselor (most centers that do genetic testing provide counseling and make it a requirement of performing the test). A listing of genetic counselors is available online from the National Society of Genetic Counselors, Inc at www.nsgc.org. Click on the image below to see my family pedigree: |
