Alumni Profile

Neurologist Maureen Leehey, '86, delves into a new neurological syndrome-FXTAS

By Camille Webb

Maureen Leehey, M.D., '86, is a neurologist specializing in movement disorders at the University of Colorado Health Science Center in Denver where she has been since completing her residency and fellowship. She is married to Aubrey Dobbs, M.D., an internist, and they have two daughters, Courtney, 11, and Katie, 9. Dr. Leehey's passion is researching a genetic disorder known as fragile X-associated tremor/ataxia syndrome or FXTAS.

What is FXTAS?
FXTAS is a neurodegenerative disorder that occurs in carriers of a ‘premutation' in the fragile X mental retardation 1 (FMR1) gene. FMR1 normally has a region that consists of three nucleotides (CGG) that is repeated five to 40 times, but when the CGG is repeated 55 to 200 times, it is called a premutation. Premutation carriers have been thought to be asymptomatic until recently, when it was found that 20 percent of women develop early menopause and, very recently, when my colleagues and I found that men over age 50 are at high risk of developing FXTAS. Women may also develop FXTAS, but it is much less common. Affected persons have progressive ataxia, tremor, and cognitive dysfunction. Ataxia, balance, and incoordination are the major symptoms. Since this disorder has only recently been described, many physicians do not recognize it and give affected persons other diagnoses such as Parkinson's disease, essential tremor, dementia, or stroke. Often they are told their symptoms are simply due to aging. FXTAS affects about one in 8,000 men over age 50, is a common cause of ataxia, and it's prevalence appears to be similar to that of other neurodegenerative disorders such as parkinsonism plus, spinocerebellar ataxia, and ALS (Lou Gehrig's disease).

How is FXTAS inherited?
Usually what happens is a child is born with fragile X syndrome, which is caused by a ‘full mutation' in FMR1, meaning the CGG is repeated greater than 200 times. Fragile X syndrome – a very different disorder from FXTAS – is a neurodevelopmental disorder and a common cause of mental retardation, severe behavioral problems, and autism. The mother is a premutation carrier and inherited the premutation from her mother or father. These grandparents of the child with fragile X syndrome, however, are usually unaware they are carriers. If persons with FXTAS were identified more readily, then families could receive proper genetic counseling to understand their risks. Unfortunately, many families have more than one child with fragile X syndrome before the disorder is recognized.

Is there a cure for FXTAS?
No, but there are medications that are effective in treating some of the symptoms.

How did you become interested in researching this disorder?
I work with a developmental pediatrician, Randi Hagerman, M.D., who is an expert on fragile X syndrome. She and I were working together at the University of Colorado in 1998 when she noticed that the moms of fragile X children would often report that one of their parents had Parkinson's disease, tremor, or balance difficulties. So, Randi sent some of these grandparents to me, since I'm a movement disorders neurologist. All were premutation carriers over age 50, and all had a unique syndrome that had not been described before.

Has your research on FXTAS been published?
Yes. We published in 2001 in Neurology. The article generated a lot of attention. One reason that this syndrome is important is because it brought attention to a pathogenic mechanism that's just now being better understood. This mechanism, called messenger RNA toxicity, causes another neurodegenerative disorder, myotonic dystrophy. We believe RNA toxicity is a major cause of FXTAS and perhaps of other disorders. Research on this new mechanism will help combat neurodegeneration in the elderly population.

In this day and age, it is an exciting and unique opportunity to be able to describe a new neurological syndrome. Since our discovery, our research group has been able to examine over 100 affected persons. This has enabled us to publish findings on the clinical and autopsy signs, prevalence, natural history of FXTAS, and its cause.

Do you have other research interests?
Yes, I am also involved in a number of clinical trials on Parkinson's disease. As a lead investigator in the Parkinson Study Group, I try to help in the international effort to find a way to slow down the disorder.

Why did you decide to attend medical school?
I had earned a B.S. from the UT-Houston nursing school and had worked as a nurse for about five years. I would often ask physicians questions but would not fully understand their answers. So, I decided it would be fun to go to medical school. However, my grades when I graduated from nursing school had not been the best. While working as a nurse at Hermann Hospital, I met Dr. "Red" Duke. He was really nice to the nurses. I talked with him about what I could do to get into medical school. He gave me advice, I followed it, and with his support and my family's, I was able to get accepted into the UT-Houston Medical School. Our medical school class was interesting because the average age of students was older. I was one of the many who had a prior career. Also, our medical school class was one of the first that had more females than was traditional back in those days.

At what point in your medical school career did you know that you wanted to specialize in neurology?
It wasn't until my last year as a medical student. It was hard for me to pin it down. I thought, ‘What specialty would be a nice lifestyle for a woman that would allow me to have a family and some free time but would also be fun and intellectually challenging?'

I considered ophthalmology and dermatology, but at the beginning of my fourth year, I did a rotation in neurology. I had so much fun on that rotation. Also, it was always clear to me without even thinking about it that the brain was the most important part of the body. If the brain isn't working, then life isn't worthwhile. Thus, I decided when I was partway through my fourth year to switch to neurology. I called Dr. Jim Grotta in the neurology department for advice, and he recommended some places to go interview. I quickly sent out applications for neurology. While neurology has always been the right choice for me, I have found that juggling an academic career and family life can at times be a real strain.

How did medical school prepare you for your current position?
I found that UT-Houston provided a lot of exposure to the many different options to focus your career on. The rotations were set up so that we would do general medicine and surgery early in the third year, and at the same time, we were exposed to medical and surgical subspecialties. Then you could choose rotations of interest. Also, throughout my four years of study, the school seemed to have a lot of layers of help. No matter what your problem was, you knew you could go somewhere to get help. Further, the faculty in general were easily available for help and advice. One thing that was missing in our curriculum, however, was classes on how to handle your money once you started making some.

Do you have any fond memories from Medical School?
Oh yes – many. One thing I particularly enjoyed was the dance parties on Friday nights in the cafeteria. I would stay in the LRC (the library) to study until about 9 p.m. and then walk over to the party. The parties were for medical students, and many residents would attend also. I have many other fond memories also of just interacting with my colleagues at the school and outside of school. The Freshman Retreat at the beginning of the year was a great way to get to know your class.