Clues To Oculopharyngeal Muscular Dystrophy Sought in New Mexico Families

TUCSON, Ariz., Nov. 26, 2001 — Two MDA-supported researchers are part of a team that has identified a group of Hispanic families with oculopharyngeal muscular dystrophy (OPMD). The rare form of muscular dystrophy was previously thought to affect mostly French Canadians and an ethnic group known as Bukhara Jews in Israel.

The results of the family identification study, which found 216 cases of OPMD in 39 kinship networks, are published in the Nov. 21 issue of the Journal of the American Medical Association.

Biologist David Bear, chairman of the Department of Cell Biology and Physiology and pathologist Mark Becher, both at the University of New Mexico Health Sciences Center in Albuquerque, are members of a multidisciplinary team pooling its efforts to study OPMD in New Mexico, particularly in the northern part of the state. The team has included physicians, scientists, genetic counselors and even anthropologists.

By studying the identified families with OPMD, scientists hope to learn more about the disease’s mechanisms, genetics and possible treatments.

OPMD, which affects both sexes, usually makes itself apparent in the 30s to 50s. The major signs, reflecting weakness of specific muscles, are drooping eyelids and difficulty swallowing. Weakness in the arms and legs sometimes occurs.

Although symptoms can range from troublesome to disabling, many families have considered the problem a collection of family traits rather than a specific disorder and therefore haven’t sought medical treatment, Bear said. He added that this misperception has been compounded by a lack of awareness of OPMD on the part of many medical professionals.

Bear said his group is taking a "two-pronged approach — to reach patients and also to educate health care workers in the northern part of the state to recognize the disease."

Bear’s MDA-supported role in the project has been to shed light on the basic biology underlying OPMD.

The genetic defect in the disease — an extra piece of DNA called a trinucleotide repeat, located on chromosome 14 — was identified in 1998 by a team that included MDA-supported Guy Rouleau at McGill University in Montreal.

"The thing that’s amazing for me is that [OPMD] is a problem that goes all the way from fundamental molecular biology to cell biology to tissue and organ biology and now extends into population biology and population health," Bear said. "It’s a really interesting and important paradigm for how basic science can be important for disease diagnosis, treatment and prevention, and MDA is leading the way in supporting this kind of research."

Genetic testing is commercially available to diagnose OPMD, while surgical and other approaches can be used to treat the eyelid and throat muscle weakness.

MDA is working to defeat more than 40 neuromuscular diseases through programs of worldwide research, comprehensive services, and far-reaching professional and public health education.

For more information about MDA’s programs, call (800) 572-1717 or go to www.mda.org or www.mdaenespanol.org on the Internet.