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Genetic Counseling

Genetic Testing

Research laboratoryclick to enlarge photograph

Research laboratory

Genetic testing is recommended for anyone diagnosed with or suspected of having TSC, as well as for all immediate family members if the individual's mutation has been identified. Although the test is not currently used to diagnose TSC, it is often used to confirm a clinical diagnosis. Mutations that cause TSC may be found anywhere on the two genes—TSC1 and TSC2—associated with the disorder. In fact, in approximately 15 percent of people diagnosed with TSC, a mutation is never found. However, once a particular mutation is located for someone clinically diagnosed with the disorder, examining the DNA of family members for that specific mutation is relatively simple.

Geneticists expect that in the future, genetic testing will be able to tell us far more than it can today about our risk of disease. Someday soon, tests will likely be sensitive enough to screen the general public for a wide array of genetic disorders, including TSC. This will ultimately help people who are mildly affected by TSC know they have the disease and make informed reproductive decisions in the future. Currently, however, doctors do not recommend that the general public with no pre-existing risk factors for TSC undergo genetic screening for the TSC mutation.

Another goal of current research into TSC is to explain why some people with TSC are severely affected while others are only mildly affected. Researchers hope to find a genetic cause to explain the variability. If they can do this, they may be better able to predict the problems an individual will encounter by looking at his or her genes.

Next Steps

It is important to remember:

  • Physicians who specialize in TSC routinely refer recently diagnosed individuals and family members to genetic counselors.
  • Genetic counseling is one of the best ways of gaining knowledge about TSC, especially as it relates to a particular family.
  • Genetic counselors help family members determine where and when a TSC mutation arose in their family.
  • Genetic counselors help parents understand that they could not have caused or prevented TSC in their child.
  • Most people with TSC and their immediate family members undergo complete physical examinations and genetic testing as a part of genetic counseling.
  • Genetic counselors help adults who have TSC understand the risk of passing their mutation on to their children.
  • Genetic counselors inform families affected by TSC of the options available to them regarding reproduction and other health decisions.
  • Most genetic counselors provide families with a complete written report of their counseling sessions, to serve as an important medical reference in the future.
  • Genetic counselors can also provide brochures and Web sites about the technical information that was discussed during the sessions.

Relevant Specialists

Genetic Counselor

A genetic counselor is a healthcare professional who has advanced degrees in medical genetics and counseling. Counselors receive training in how to explain the causes of genetic disease, how to assess the risk of, or avoid, passing a genetic disorder to the next generation, and how to advise patients and families with regard to their medical options in the face of a genetic disease. Genetic counselors also provide supportive counseling to families, serve as patient advocates, and refer individuals and families to community or state support services.


A geneticist is a medical doctor who specializes in the diagnosis and care of individuals with genetic disorders. Geneticists are able to analyze genetic test results and assess the risk of passing a genetic disorder on to future generations. Geneticists who specialize in treating people with TSC are trained to advise patients with regard to medical and reproductive choices.

You can find a list of on-staff physicians on the Herscot Center for Children and Adults with TSC Web site.


Athena Diagnostics
Athena Diagnostics lab provides molecular diagnostic testing for neurological disorders including tuberous sclerosis complex.

The GeneTests Web site is used by genetic counselors and geneticists and provides current information on genetic testing and genetic services.

Genetics Home Reference
The Genetics Home Reference Web site is a service of the U.S. National Library of Medicine. It provides a guide to understanding genetic conditions.

National Society of Genetic Counselors
The National Society of Genetic Counselors can help families locate a genetic counselor in their area.

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This content was last reviewed on March 30, 2006.