Tuesday, October 21, 2014
Inherited Disorders and Birth Defects
Autoimmune Diseases run in families?
My paternal cousin has Type 1 diabetes, my paternal grandmother and my mother have hypothyroidism, and my father has Sjogren`s syndrome (all were first diagnosed at around my current age, 28 +/- 5 years). I have some varied symptoms that don`t seem to fit into any particular AI disease, but it seems like I should have a really good chance of developing one. Are there any statistics on developing an AI disease when it is in your family on both sides? Just looking for some numbers. Thanks!
As you know, the immune system normally helps fight off infections and other toxic exposures by producing lymphocytes to attack the exposure. If a person’s own lymphocytes react against its own body that is called an autoimmune reaction. Usually lymphocytes are suppressed until needed. While some autoimmunity occurs naturally in everyone, it does not usually result in diseases. Autoimmune diseases happen when the normal processes are disturbed and lymphocyte control is not normal - this allows the lymphocytes to no longer recognize the body as itself and instead, attacks the body. This leads to a whole list of diseases.
It is now well established that for some families, there is a strong genetic predisposition to develop an autoimmune disorder such as in your family. However, it is complex inheritance - that is, there is not just one gene that causes these diseases, but many and they interact with the environment (such as bacteria, viruses, toxins, and some drugs ) to actually cause disease. This also means that not everyone who inherits a predisposition will actually develop any of these disorders.
It is very difficult to find any specific figures as to what your chances would be to develop any of the disorders that are in your family. You are at increased risk; however, there is no specific number to give you. There have been some specific genes that have been found to be more associated with some disorders - for example, Sjogren’s syndrome is correlated with some specific genes in the major histocompatibility complex. But again, there are no specific numbers to tell someone what their chance is to develop the disorder. If a person has the genes that are associated with Sjogren’ syndrome, they probably have an increased chance to develop Sjogren’s - but we do not know exactly how much.
Because you have a strong family history of autoimmune disorders, you may want to talk to a geneticist or genetic counselor to discuss these issues in detail. You can find a genetics center near you at the National Society of Genetic Counselors’ resource center - the website is below. Also The American Autoimmune Related Diseases Association has some very good information as well.
Anne Matthews, RN, PhD
Associate Professor of Genetics
School of Medicine
Case Western Reserve University