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Schizophrenia and Genetic Counseling
Genetic counseling is a health service, which is provided to people who may inherit or pass on (to their children) a hereditary illness. This service is intended to explain the genetic factors of the specific condition as well as to predict the chances of clients developing/passing on the condition. This is known as recurrence risk. It is the responsibility of the genetic counselor to help people understand these facts. Genetic counseling for psychiatric conditions such as schizophrenia is becoming more wide spread and its use is being successfully demonstrated. Potential clients should be aware that while there are many benefits of genetic counseling, it could also be distressing due to the emotional subjects discussed. In general, people who have schizophrenia within their families may be interested in learning more about the causes of the condition, and discovering whether they or their relatives will be at risk for developing the condition. Genetic counseling can answer some of these questions.
Schizophrenia is a complex condition, affecting approximately 1% of the general population. The exact causes of schizophrenia are still not well understood, however it is now thought that a number (5 to 10, or more) of different genes, as well as many different environmental influences, are responsible for an individual developing schizophrenia. Therefore schizophrenia is classified as a multifactorial syndrome. This means that schizophrenia can run in some families, although many people with schizophrenia do not have an affected relative.
Editorial Note: Dr. E. Fuller Torry (not a genetic counselor, but a well-known schizophrenia researcher and advocate) has noted in his book "Surviving Schizophrenia" the following regarding genetic inheritance of schizophrenia,
Traditionally, genetic counseling has concentrated on conditions with well-known patterns of inheritance, such as Huntington's Disease. Genetic counseling for psychiatric disorders is more complex and was first performed in the early 1980s. At present, genetic counseling is recommended for people with schizophrenia in their families, although it is not known how many people are actually offered these services. Clients needing genetic counseling may see their local counselor or they may attend a hospital, which concentrates on psychiatric conditions.
For example, the University of British Columbia in Canada and Columbia University in New York specialize in genetic counseling for psychiatric conditions. It is possible to find a genetic counselor with expertise in schizophrenia by looking on the National Society of Genetic Counselors (NSGC) web site (www.nsgc.org). All genetic counselors listed on the NSGC web site are registered with the NSGC and should have an Masters of Science (MS) in genetic counseling. Additionally, most counselors are certified or certifiable by the American Board of Genetic Counselors. Moreover, counselors with a special interest in psychiatric conditions are often registered with the NSGC psychiatric special interest group, which helps them maintain up-to date knowledge.
Calculating the recurrence risks (or the risk that schizohprenia will re-occur in a family - either in future children a couple may have, or in other existing family members) is complex. It is not yet possible to test whether an individual has specific genes (though this is changing quickly), which would increase their chances of developing schizophrenia. Therefore genetic counselors must use empiric data (figures obtained by counting how many people with schizophrenia also have specific relatives with schizophrenia), coupled with their knowledge of the client's family history. Specifically a genetic counselor may calculate risks of developing schizophrenia by using a Bayesian calculation (a type of statistical estimate) on the basis of empiric data and the client's family mental health history, alternatively it may be possible for a genetic counselor to see a clear inheritance pattern from the family history. Generally, the family history review will try to look back for three or four generations.
The counselor will also gather information about any other brain disorder diagnoses (e.g. "mental breakdown", depression, temporary psychosis, depression, bipolar disorder, schizo-affective, etc.) in the family, as these can complicate the inheritance patterns. When talking with the counselors you should be as comprehensive as possible - including all information about family mental health backgrounds that you can dig up - the more information that you can provide the counselors, the better the estimate of the risks. Some information from previous generations may be vague or not formally diagnosed (for example, in the early 1900's a person might have been said to have a "mental breakdown" - which resulted in them being temporarily treated in a psychiatric hospital, given shock treatments and released; or maybe you had a "eccentric uncle" that lived by himself in a cabin away from society and only very rarely socialized with family, and spoke of conspiracy theories when he did talk. This type of information should be conveyed to the counselors. Counselors will consider these alternative diagnoses when calculating the schizophrenia recurrence risks (i.e. the risk that schizophrenia will hit again in the family).
Generally, a genetic counseling session will last about an hour and
should be covered by health insurance in the US, while in the UK and
Canada the national health services provide counseling. Genetic counseling
provides clients with specific information, as well as helping clients
to understand and process their emotions. The benefits for clients include
gaining a thorough understanding of the causes of schizophrenia, personalized
recurrence risks, correction of misconceptions and the opportunity to
explore resulting emotions.
Specific genes have not been shown to directly cause schizophrenia, however, numerous studies have shown a variety of chromosomes to be involved in the inheritance of schizophrenia, and a number of these studies have been confirmed by independent research groups. These chromosomes are thought to contain certain genes, which increase the chance of an individual developing schizophrenia. The chromosomes thought to contain these genes include (20): chromosomes 22, 1, 18, 15, 14, 13, 12, 11, 10, 8, 6, 5, 3.
While the specific chromosomal regions are (20):
22q12.3, 22q11.2, 22q11-q13, 1q42.1, 18p, 15q15, 14q32.3, 13q34, 13q32, 12q24, 11q14-q21, 1q21-q22, 10q22.3, 8p21, 6q13-q26, 6p22.3, 6p23, 5q11.2-q13.3, 3p25.With this many chromosomes involved, the inheritance of schizophrenia is complex. There is not just one gene that causes schizophrenia. Instead, inheriting several genes causes an individual to have a higher chance of developing this condition. Genes which are thought to increase the chance of an individual developing schizophrenia include(2): the regulator of protein signaling 4 (
It is also believed that there may be biological subsets of schizophrenia, which means that different genes may cause people to have specific symptoms. One distinct subgroup of schizophrenia is known to be associated with a gene in the chromosome region 22q11.2(8). The deletion of this gene causes a syndrome known as DiGeorge, and 25% of the people with this syndrome are known to develop schizophrenia. It is thought that as the genetics of schizophrenia become better understood, other biological subgroups will be identified.
Overall, the exact cause of schizophrenia is difficult to determine, however, it is very clear that there is a genetic component to this disorder. It would therefore seem important that individuals with schizophrenia or individuals who have a family member with schizophrenia, receive genetic counseling. To date many people have published studies supporting the use of genetic counseling for people with schizophrenia and their relatives. These studies include: Tsuang etc al (2001), Papadimitriou & Dikeos (2003), A Reveley (1985), Austin & Honer (2004), Whiteford & Price (1987,) and Hogdkinson, et al (2001)
. Click on the following link for the latest news on Genetics and Schizophrenia
Who might see a genetic counselor (12)?There are many reasons why people with schizophrenia in their family might see a genetic counselor. Some of the people who might see a counselor include:
Additionally, genetic counseling is very useful for explaining the causes of schizophrenia and correcting possible misconceptions that many people have. For example, some people believe that genetic disorders are untreatable and that if someone has the gene they must develop the disease. This is NOT true. Many genetic disorders can be treated and not everybody with genes for schizophrenia will develop the condition. There have been numerous cases involving identical twins in which one twin inherits schizophrenia and the other twin does not. As identical twins must have the same exact genes, we suspect that if developing schizophrenia were a result of genetic inheritance alone that both twins would develop the disease. The other twin actually only develops schizophrenia about half the time.
Counseling sessions can also suggest preventative measures for schizophrenia, such as(1): safe guarding the health of children who are at risk for developing schizophrenia, avoiding high stress levels, and avoiding other environmental risk factors. It is also possible to help parents look for early warning signs in their children and get early diagnostic testing for schizophrenia, or periodic testing for schizophrenia. Genetic counseling for clients with schizophrenia in their families can also help demystify schizophrenia and therefore decrease the effects of potential stigma for the family. Finally genetic counseling may improve adherence to the treatment plan in some patients, once they better understand schizophrenia.
1. Gathering information
2. Assessing risk
3. Conveying information
4. Providing support and facilitating decision making
5. Follow up support
1. Gathering Information / Family History
Information about the client’s family history and diagnoses may be gathered at the beginning of the appointment. Alternatively, the genetic counselor may telephone the client before hand, enabling the counselor to obtain any necessary medical records prior to the appointment.
* These are averaged figures from several studies. For more specific figures and explanation, contact your nearest genetic counselor.
The chance of an individual developing schizophrenia also decreases as they become older and remain symptom free. This is because people normally show symptoms of schizophrenia in their early 20s, if they are male, or late 20s, if they are female. For example, a person over 55 who is symptom free has basically no chance of developing schizophrenia, while a person over 40 has a much-reduced risk (26). Additionally, recurrence risks can be complicated by the presence of other related mental illnesses in the family such as schizoaffective disorder. Therefore it is very important that a competent counselor calculates the recurrence risks individually for each client.
Providing support / facilitating decision making
genes linked with schizophrenia are validated by additional research
studies, it MAY be possible to test for these genes either before birth, or before
an individual shows symptoms. This testing would allow the genetic counselor
to more accurately determine the chance of an individual developing
schizophrenia, and work with psychiatric doctors to potentially take
actions to prevent the development of schizophrenia. This has the to
potential to create ethical and moral dilemmas for the client and therefore
the genetic counselor would help the client to make the necessary decisions.
Another goal of medical research today is to develop additional therapies
to prevent or cure people who have the genes that predispose them towards
getting schizophrenia. The goal of gene
therapy research is to allow slight targeted modification of sections
of genes (that predispose a person towards develping schizophrenia)
to an alternative version of the same gene (like editing a mistake in
computer document with a word processor). If this were done early in
life, it could dramatically reduce or potentially eliminate the risk
of schizophrenia for a child. Another important area of research is
that of stem
cell research. The goal
of this research is to very clearly understand the process by which
brain development may be impacted by specific variations of genes, and
potentially reverse the damage caused to the brain by inserting new
stem cells into the brain in targeted regions. (see stem
cell research and schizophrenia for more information)
Another goal of medical research today is to develop additional therapies to prevent or cure people who have the genes that predispose them towards getting schizophrenia. The goal of gene therapy research is to allow slight targeted modification of sections of genes (that predispose a person towards develping schizophrenia) to an alternative version of the same gene (like editing a mistake in computer document with a word processor). If this were done early in life, it could dramatically reduce or potentially eliminate the risk of schizophrenia for a child. Another important area of research is that of stem cell research. The goal of this research is to very clearly understand the process by which brain development may be impacted by specific variations of genes, and potentially reverse the damage caused to the brain by inserting new stem cells into the brain in targeted regions. (see stem cell research and schizophrenia for more information)
counselors at the
How to Contact a Genetic Counselor
Schizophrenia and Genetic Risks - designed for families (Booklet in .PDF format) - this booklet is rather old (probably over 5 years old - so a out of date considering how fast the field of genetics is moving - but written by knowlegeable people).
(**) Information from personal correspondence with researchers
(Note - all the following papers should
have abstracts for the articles at www.pubmed.org
(Note - all the following papers should have abstracts for the articles at www.pubmed.org
1. Austin, J.C. & Honer, W.G. 2004, "The potential impact of genetic counseling for mental illness", Clinical Genetics, vol. 10.1111, pp. 1.
2. Austin, J. 2005, Schizophrenia: An update and review, Journal of Genetic Counseling, Vancouver.
3. Bains, W. 1989, "Genetics of schizophrenia", Nature, vol. 337, no. 6206, pp. 402.
4. Bassett, A. 2001, "Psychiatric genetics in the 21st Century", Canadian Journal of Psychiatry, vol. 46, no. 2, pp. Editorial.
5. Bassett, A.S., Chow, E.W., Weksberg, R. & Brzustowicz, L. 2002, "Schizophrenia and genetics: new insights", Current psychiatry reports, vol. 4, no. 4, pp. 307-314.
6. Davis, J.O. & Phelps, J.A. 1995, "Twins with schizophrenia: genes or germs? ", Schizophrenia Bulletin, vol. 21, pp. 13.
7. Geddes, J.R. & Lawrie, S.M. 1995, "Obstetric complications and schizophrenia: a meta-analysis. ", British journal of psychiatry, vol. 167, pp. 786.
8. Hodgkinson, K.A., Murphy, J., O'Neill, S., Brzustowicz, L. & Bassett, A.S. 2001, "Genetic counselling for schizophrenia in the era of molecular genetics", Canadian journal of psychiatry. Revue canadienne de psychiatrie, vol. 46, no. 2, pp. 123-130.
9. Jones, P. & Cannon, M. 1998, "The new epidemiology of schizophrenia.", Psychiatry of clinics in North America, vol. 21, pp. 1.
10. Kay, D. W. K. 1978, "Assessment of Familial Risks in the Functional Psychoses and their Application in Genetic Counselling", Brit. J. Psychiat., vol. 133, pp. 385.
11. Kendler, K.S. & Hays, P. 1982, "Schizophrenia with premorbid inferiority feelings. A distinct subgroup?", Arch Gen Psychiatry, vol. 39, pp. 643.
12. Kessler, S. 1980, "The genetics of schizophrenia: a review", Schizophrenia bulletin, vol. 6, no. 3, pp. 404-416.
13. Korner, J., Rietschel, M., Nothen, M.M. & Propping, P. 1996, "Genetic counseling in psychiatric diseases", Der Nervenarzt, vol. 67, no. 1, pp. 3-14.
14. Kringlen, E. 1997, "Genetic information and counseling in psychiatry?", Tidsskrift for den Norske laegeforening, vol. 117, no. 16, pp. 2347-2350.
15. Meltzer, H.Y. 2000, "Genetics and Etiology of Schizophrenia and Bipolar Disorder", Biological Psychiatry, vol. 47, pp. 171.
16. Moldin, S. 1999, "Genetics and mental disorders. Summary of research", Biology Psychiatry, vol. 46, pp. 56.
17. Morton, L.A., Kidd, K.K., Matthysse, S.W. & Richards, R.L. 1979, "Recurrence risks in schizophrenia: are they model dependent?", Behavior genetics, vol. 9, no. 5, pp. 389-406.
18. Mosher, K. 2003, Assessing the psychological impact of predictive testing for Huntington disease on young adults / Kara Mosher., Masters edn, Sarah Lawerence College, New York.
19. Murray, R.M., Reveley, A. & McGuffin, P. 1986, "Genetic vulnerability to schizophrenia. ", Psychiatry of clinics in North America., vol. 9, pp. 3.
20. National Center for Biotechnology Information 2005, , Schizophrenia. Available: www.ncbi.nlm.nih.gov [2005, .
21. Papadimitriou, G.N. & Dikeos, D.G. 2003, "How does recent knowledge on the heredity of schizophrenia affect genetic counseling?", Current psychiatry reports, vol. 5, no. 4, pp. 239-240.
22. Pardes, H., Kaufmann, C.A., Pincus, H.A. & West, A. 1989, "Genetics and psychiatry: past discoveries, current dilemmas, and future directions", The American Journal of Psychiatry, vol. 146, no. 4, pp. 435-443.
23. Propping, P. 1980, "Genetic counseling in schizophrenia", Deutsche medizinische Wochenschrift, vol. 105, no. 8, pp. 273-276.
24. Rainer, J.D. 1980, "Genetics in Psychiatry" in Comprehensive textbook of psychiatry, eds. H.I. Kaplan, A.M. Friedman & B.J. Saddock, 3rd edn, Williams & Wilkins, Baltimore.
25. Reiss, D., Plomin, R. & Hetherington, E.M. 1991, "Genetics and psychiatry: an unheralded window on the environment", The American Journal of Psychiatry, vol. 148, no. 3, pp. 283-291.
26. Reveley, A. 1985, "Genetic counselling for schizophrenia", The British journal of psychiatry; the journal of mental science, vol. 147, pp. 107-112.
27. Rutter, M. 1997, "Implications of genetic research for child psychiatry", Canadian journal of psychiatry. Revue canadienne de psychiatrie, vol. 42, no. 6, pp. 569-576.
28. Schulz, P.M., Schulz, S.C., Dibble, E., Targum, S.D., van Kammen, D.P. & Gershon, E.S. 1982, "Patient and family attitudes about schizophrenia: implications for genetic counseling", Schizophrenia bulletin, vol. 8, no. 3, pp. 504-513.
29. Shore, D., Berg, K., Wynne, D. & Folstein, M.F. 1993, "Legal and ethical issues in psychiatric genetic research", American Journal of Medical Genetics, vol. 48, no. 1, pp. 17-21.
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31. Torrey, E.F., Miller, J., Rawlings, R. & et al 1997, "Seasonality of births in schizophrenia and bipolar disorder: a review of the literature. ", Schizophrenia Research, vol. 28, pp. 1.
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33. Tsuang, D., Faraone, S. & Tsuang, M.T. 2001, "Genetic Counseling for Psychiatric Disorders", Current Psychiatry Reports, vol. 3.
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Note: This document was written in March, 2005 and was written by V. Lyus, a student studying for her Masters of Science in Genetic Counseling (the document was also edited slightly by schizophrenia.com, and the editorial comment at the top of the document added).