Ask the Experts: Genetics Questions
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Q: I'm a 25-year-old female diagnosed with MS 7 years ago. My maternal grandfather also had MS...
Q: My Mother was diagnosed with MS 2 years ago, my sister just got diagnosed with MS. I have been hospitalized with numbness on one side of my body, and I have memory issues and have had blurry vision that seems to be getting worse. I also have balance issues. Should I get tested?
A: The short answer to your question is yes, but- The investigation should not be limited to consideration of MS. A person with the symptoms you describe should have a careful neurologic evaluation. It would seem prudent to advise your primary physician of the symptoms are ask for specific suggestions. If you do not have a primary physician, an MS center would be a reasonable alternative place to start. Should you need assistance locating an MS Center or MS neurologist, please call the Society’s Information and Resource line at 800-344-4867.
Arthur Safran, MD
February 2013
Q: My husband has just been diagnosed with MS. His Mom passed away in 1999 at the age of 59, from complications of MS.
We have stored our child's cord blood for any future treatment/cure for MS. Might our family's genetics be "helpful" for anyone's research into Multiple Sclerosis and might cord blood ever be considered helpful in the near future?
A: MS is a neurological disease that has an inherited or genetic component, likely in the form of a susceptibility or predisposition to the disease. However, most patients with MS do not have a family history, and other non-genetic factors are certainly important in the pathogenesis or development of this condition. Twin studies illustrate this point. If one identical twin is affected, there is about a 35% chance that the other twin will develop MS. If MS was solely a genetic disease, that figure would be 100%!
The Multiple Sclerosis Genetics Study is a multi-center research project dedicated to understanding the genetics of MS. The goal of the study is to identify which genes make a person more susceptible to MS. As part of the study, DNA, the building blocks of the genetic code, are extracted from a blood sample and used in genetic analysis. This large nationwide study is attempting to refine the results from earlier, smaller studies by using new tools and more advanced technologies in a very large number of MS patients as well as healthy controls.
There are a number of centers in New England that are participating in the MS Genetics Study. If you would like to participate or learn more about this research, please contact the Central New England Chapter of the NMSS to find out more information. This research would not be utilizing cord blood, but your husband could certainly participate! Thanks for a great question, and good luck as you and your husband move forward !
Ellen Lathi, MD
March 2008
Q: I'm a 25 year old female diagnosed with MS 7 years ago. My maternal grandfather also had MS. He went down hill really quickly. Within 10 years he died from complications of the disease. I do believe MS can be inherited or genetically passed on. My question is, I was told that MS is the opposite of AIDS/HIV. Is that true? MS is too strong and attacks the immune system, and with AIDS/HIV you're immune is too weak to fight off viruses? If they find a cure for MS, then they have a cure for AIDS/HIV or vice versa?
A: The first part of your question relates to the genetic basis of MS. While MS is not simply a genetic disease such as muscular dystrophy where a single rare mutation is inherited, there is a strong genetic component to MS. So, if an MS patient has an identical twin, the odds of that twin developing the disease are between 20% and 40%. In contrast, a fraternal twin has about a 1% chance of developing MS. We hope that in the next few years, we will be able to map the genes that are linked to MS. I say genes, because in a complex genetic disease such as MS, we talk about a combination of common susceptibility genes that come together to induce the risk of developing MS.
Regarding the second part of your question, the relationship between MS and HIV is not as simple as you were told. The Human Immunodeficiency Virus (HIV) infects CD4 T cells, eventually inducing a state of profound immunosuppression (underactive CD4 T cells) leading to so called opportunistic infections by parasites and other viruses. We believe MS is an autoimmune disease caused by an over active CD4 T cell recognizing myelin antigens, leading to CNS inflammation and myelin destruction. We can treat MS by drugs that induce immunosuppression, such as cyclophosphamide and mitoxanthrone. This is probably the basis for what you have been told. However, research to find treatments for HIV is now based on blocking HIV (viral) replication and are unlikely to help in MS. Similarly, drugs that induce better immunosuppression will not help patients with AIDS. However, both fields deal with understanding the immune system, so fundamental discoveries in the field of immunology will help the understanding of both diseases. In fact, our interdependence on each other in fields of clinical immunology has lead to a new meeting to induce interdisciplinary work in the field of immunology, the "Federation of Clinical Immunology Societies" (http://www.focisnet.org/)
David A. Hafler, MD