Diseases are defined as rare in the US when they affect fewer than 200,000 people. While the number may seem low, over 7,000 rare disease have been identified and the National Institutes of Health (NIH) estimates that rare diseases collectively affect over 25 million Americans.

Rare diseases can be very complex to treat due to lack of understanding, little to no options for treatment and limited funding. But it is for these reasons that raising awareness and supporting research and funding for rare diseases is so important.

In honor of Rare Disease Day this year, we are highlighting a rare disease called neuromyelitis optica (NMO). Mass General neurologist Farrah Mateen, MD, PhD, has been studying NMO for over 10 years, and has dedicated her clinical practice to NMO, multiple sclerosis (MS), and other diagnostically and therapeutically complex conditions.

What is NMO?

NMO stands for neuromyelitis optica, which is an autoimmune disease that affects the brain, spinal cord and eyes. It causes inflammation and demyelination in these parts of the central nervous system.

Demyelination, a key aspect of NMO, is the destruction of myelin, the protective covering of nerve cells. When the myelin surrounding a nerve cell is destroyed, the cell loses the ability to effectively transfer signals.

The combination of inflammation and demyelination leads to NMO “attacks,” which is how NMO presents itself. Each attack can destroy more and more myelin and lead to long term damage.

NMO attacks range in severity and duration, and can result in difficulty with sight, strength, sensation and bladder control along with severe nausea and vomiting.

There are no known risk factors and it does not follow any recognized genetic pattern, but an antibody called anti-aquaporin-4 (anti-AQP4) is found in most cases.

Aquaporin-4 (AQP4) is a water channel protein found in the brain and central nervous system. During an NMO attack, the anti-AQP4 antibody targets the AQP4 protein, causing destruction. Since AQP4 is found in higher concentrations in the optic nerves and spinal cord, these are the areas that suffer the most during and after NMO attacks.

Once a person has suffered from an NMO attack, it is likely many attacks will occur in the future. Severe and frequent attacks can lead to blindness, paralysis, numbness, and loss of control of bladder and bowel function, and the effects are often irreversible.

Since there is currently no cure for NMO, the goal for treatment is to limit the number of attacks.

How is it diagnosed?

One of the challenges with NMO is that people do not know they have it until they experience an attack.

The only way to diagnose NMO is to test the patient for anti-AQP4, and the test will only come back positive after an attack. This means there is no way to prevent NMO, there are only ways to test for it and manage the attacks after the patient tests positive.

Another challenge is that people are often misdiagnosed with MS, and the treatments are different.

NMO and MS both involve the deterioration of myelin in the central nervous system. While the symptoms are similar, NMO attacks tend to be more severe and less reversible, making early detection and treatment of NMO critical.

What research is being done?

As with many rare diseases, very little is known about what exactly causes NMO, making it difficult to prevent. To learn more about NMO Dr. Mateen and her team are looking into the pathology of NMO, but also equity and how it affects access to testing and treatment.

In one of her latest studies, Mateen and her team surveyed 60 countries to determine the access and affordability of NMO diagnostic testing and treatment. The study found that majority of the respondents reported having access to treatment, but only a fraction reported access to diagnostic tests.

Each diagnostic test is estimated to cost about 200 dollars, while one novel treatment is estimated to cost about 500,000 dollars per year. One potential avenue Dr. Mateen and her team are proposing is to partner with pharmaceutical companies for disease education outreach to increase access to diagnostic tests that are essential for NMO to improve treatment equity around the globe.

Dr. Mateen’s study was conducted with the help of a grant from The Sumaira Foundation for NMO, a nonprofit organization dedicated to generating global awareness of neuromyelitis optica, fundraising to find a cure, and creating a community of support for patients and their caregivers.

The Sumaira Foundation for NMO

Sumaira Ahmed was an up-and-coming model and actress in India and Bangladesh before she moved to Boston to pursue a degree and career in public relations at Boston University’s College of Communication.

In the summer of 2014, she was diagnosed with sero-negative neuromyelitis optica/CRION after losing vision in her right eye. Shortly after, she founded The Sumaira Foundation for NMO (TSF) geared towards generating global awareness and finding a cure for neuromyelitis optica. Sumaira’s founding philosophy has always been that heightened awareness could result in increased funding for research to get closer to a cure.

In 2015, Sumaira became the 1st Miss Bangladesh-USA advocating for equal opportunity education for the children of Bangladesh to increase tolerance and strengthen the country’s international presence, economy, and infrastructure.

“From what I have seen, NMO patients endure the most and complain the least. I am eternally grateful for getting NMO because there is really no greater privilege than to serve and advocate for a community of warriors like these patients. I am hopeful, that in due time, with everyone’s help, we will no longer have to suffer in silence.”

Sumaira Ahmed

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