February 8, 2013
NIH Podcast Episode #0181
Balintfy: Welcome to episode 181 of the new NIH Research Radio. The new NIH Research Radio is your source for weekly news and information about the ongoing medical research at the National Institutes of Health – NIH . . . Turning Discovery Into Health®. I'm your host Joe Balintfy, and coming up in this episode our news summary at the end of the program includes items on
- a way people with incomplete spinal cord injuries may be able to improve mobility
- how a specific protein may play a role in aggressive forms of breast cancer, and
- a gene variation linked to aortic valve disease.
But first, our feature story on Marfan syndrome.
Marfan syndrome and its effects on vision
Balintfy: February is National Marfan Awareness Month so I’m talking with Dr. Wadih Zein here at NIH. Dr. Zein is a clinician at the NIH’s National Eye Institute. And first Dr. Zein, could you tell me what exactly is Marfan syndrome?
Zein: Marfan syndrome is an inherited disease that affects the connective tissue of the body. Connective tissue is present throughout the body and holds the different tissues together. Because of that, Marfan syndrome affects multiple systems in the body, multiple organs including the eyes, the heart, and blood vessels, the skeleton, the skin, and the lungs.
Balintfy: You mentioned the eyes first. Is that how it’s typically diagnosed, with an eye exam?
Zein: Often the eye exam can lead to a diagnosis of Marfan syndrome. The typical diagnosis however involves a look at all the systems together and then hopefully the clinician would be able to put all the symptoms and science together and come up with a diagnosis or a presumptive diagnosis. This diagnosis can be confirmed by doing the genetic testing.
Balintfy: How common is Marfan syndrome?
Zein: Marfan syndrome is one of the more common hereditary diseases. It affects around 1 in 7,500 people and as such has been diagnosed in around 200,000 people in the United States. Around three quarters of Marfan syndrome patients have a family history of the disease and the other 25% occurs in a patient who has no family history of the disease.
Balintfy: What kind of treatments are available for people with Marfan syndrome?
Zein: The treatment depends on the finding. So for example if the patient has a high degree of myopia then that can be corrected with eye glasses or with contact lenses and the same applies to the astigmatism that is noted in Marfan syndrome. This is usually more challenging than your typical refractive error of correction.
Balintfy: Why Dr. Zein?
Zein: Given the fact that it’s often a changing aspect of the disease. So a lot depends on the curvature of the cornea and a lot depends on the lens itself. The patients who have Marfan syndrome tend to develop a change in their refractive error and that needs to be corrected accordingly.
Another rather common manifestation of the disease is the weakness in the zonules of the lens of the eye – the web-like structures that hold the lens in place – and this can lead to significant difficulties. In addition to the difficulties with the refractive error, the weakness in the zonules can cause glaucoma and can cause a displacement of the lens itself creating a reduction in the visual potential of the patient.
Balintfy: And that might mean that that dislocated lens should be removed and if so when?
Zein: So that’s a very good question that’s often encountered in the clinic and that’s often difficult to answer appropriately except on a case by case basis.
Removing the lens in a patient who does not have Marfan syndrome is a procedure that has a slight amount of risk but that has a significant potential or benefit. In the case of patients who have Marfan syndrome, the risk is much higher. Given that the zonules are weak and the zonules since they are the structures that hold the lens in place are necessary when undergoing cataract surgery in the manner that surgery is being done these days and because of that the surgery itself, becomes challenging.
Another aspect of the problem lies in the fact that after removing the lens a big question mark is encountered in whether to place an intraocular lens or not following the procedure. So again the Marfan syndrome patient is typically nearsighted significantly so and because of the weak zonules, it’s always a challenge to think about whether an intraocular lens should be placed and then run the risk of displacement of the lens and also surgically it’s more of a challenge to perform the surgery, to remove the lens, and then to fix a new intraocular lens in is place.
Balintfy: Is there research that’s currently being done on Marfan syndrome?
Zein: There’s a lot of research that is being done on Marfan syndrome. This research involves the different aspects of the disease as well as the molecular genetic knowledge of the disease. This research tends to be both basic science research as well as clinical research.
Balintfy: And basic research as well as clinical research, what’s the difference there?
Zein: Yes. So clinical research involves research done on patients and basic science research is really a research to understand the disease mechanisms better. It typically would involve either a cell model or an animal model of the disease. As I had mentioned, both clinical and basic science research is being undertaken to understand the disease better and to try to find treatments.
Balintfy: What do you think is important to emphasize about Marfan syndrome?
Zein: So I just would like to mention that one of the more serious organs that is involved in Marfan syndrome is the cardiovascular system and because of that, I think it’s especially important for the diagnosis to be made early and for the patient to be appropriately referred and for the appropriate tests to be performed. I also think that it’s very important for the Marfan syndrome patient to have an adequate follow-up that involves multiple clinicians and I think that by itself is a very important feature of the medical management of the Marfan syndrome patient.
I would like to also mention that because of these advances in following up and treating the patients who have Marfan syndrome, because of the additional awareness of the disease among the clinicians, I would like to point that the lifespan of the Marfan syndrome patient has been significantly increased. So that the patients right now have an average lifespan of around 70 years rather than the 45 years that was typical in earlier days.
Balintfy: It sounded to me like this is a syndrome where it’s not just going to be one healthcare provider. It could be the eye doctor or the primary care physician, the cardiologist, a number of people would be involved in figuring out.
Zein: You’re perfectly right. So this is a syndrome where multiple systems are involved and because of that it’s a multispecialty syndrome. So the best care usually involves the cooperation of more than one clinician in more than one discipline. Obviously, the primary caregiver is going to have to follow up the patient on a regular basis. Regular follow-ups with the ophthalmologist, the cardiologist are really important but also depending on the findings, the patient might have to follow up with a specialist to look at the lungs, the pulmonary system, the skeletal system, and the skin.
Balintfy: Very good. Thank you very much.
Zein: Thank you.
Balintfy: Again that’s Dr. Wadih Zein at the NIH’s National Eye Institute. For more on Marfan syndrome, visit www.niams.nih.gov. And coming up, the latest news on spinal cord injuries, breast cancer, and aortic valve disease. That’s next on NIH Research Radio.
(BREAK FOR PUBLIC SERVICE ANNOUNCEMENT)
Balintfy: Now for some recent news headlines from NIH, here’s Craig Fritz.
Fritz: According to a study supported by NIH, a training regimen to adjust a patient’s reflexes may help improve mobility for some people with incomplete spinal cord injuries. People with incomplete spinal injuries have some level of nerve activity below the injury sight. During training, the participants were instructed to suppress a jerk-like knee reflex elicited by a small shock to the leg. Those who were able to calm hyperactive reflexes — a common effect of spinal cord injuries — saw improvements in their walking.
A protein associated with conditions of metabolic imbalance, such as diabetes and obesity, may play a role in the development of aggressive forms of breast cancer, according to new findings by researchers at NIH. Metabolic imbalance is often caused by high carbohydrate intake, which can lead to over-activation of a specific molecule. This over-activation can increase the risk of breast cancer. Scientists say that maintaining a healthy diet, combined with developing drugs to reduce the molecule’s activity, may one day lead to a way to break the link between cancer and obesity.
NIH researchers have found a gene variant linked to aortic valve disease. The variant doubles the risk of calcium buildup in the heart’s aortic valve. Calcium buildup is the most common cause of narrowing of the aortic valve and can lead to heart failure, stroke, and sudden cardiac death. Scientists say this new breakthrough may offer new therapies for problems with the aortic valve. Currently, there are few viable treatments besides major surgery to replace the valve.
For this NIH news update, I’m Craig Fritz.
Balintfy: You can get more information on these news items at www.nih.gov/news.
Balintfy: And that’s it for this episode of the new NIH Research Radio. Please join us again next Friday, February 15 when our next edition will be available. Coming up in that episode…
Researchers and physicians have identified over 70 different types of sleep disorders and some of them are very common.
If you have any questions or comments about this program, or have a story suggestion for a future episode, please let me know. Send an email to NIHRadio@mail.nih.gov. Also, please consider following NIH Radio via Twitter @NIHRadio, or on Facebook. Until next week, I'm your host, Joe Balintfy. Thanks for listening.
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