Muscular Dystrophy

Researchers Identify a Muscular Dystrophy Gene

Medical School Researchers John Day and Laura Ranum have identified the gene that causes the most common form of muscular dystrophy in adults—thanks in part to an extended northern Minnesota family of German descent.

By Sarah Youngerman
PICTURES OF HEALTH, Academic Health Center, 2001  

The gene on chromosome 3 causes myotonic dystrophy Type 2 (DM2)—which affects the eyes, heart, hormonal systems, blood, and muscles. The findings were reported in the August 3 issue of Science. As part of their study, Day and Ranum tested 60 members of a family in northern Minnesota known to carry the disease. The disorder is relatively common in Germany and in Minnesota families of German ancestry. While therapies for prevention and treatment are still to be found, researchers believe the discovery will lead to earlier diagnosis and better management of the disease. “These findings enable us to genetically screen those people with symptoms of the disease and even those who are asymptomatic, but related to someone with the disease,” said Day, associate professor, department of neurology and the Institute of Human Genetics.

The discovery comes nearly 10 years after scientists in Germany and Texas uncovered a genetic mutation on chromosome 19, which also causes one form of myotonic dystrophy (DM1). Day and Ranum collaborated with the scientists to find the underlying genetic mutation and concluded that abnormal RNA causes both DM1 and DM2.“RNA is the messenger molecule that translates the DNA code into proteins,” said Ranum, an associate professor in the department of genetics, cell biology, and development. “In the past, researchers thought that RNA had little or no direct role in causing disease. Our findings indicate that additional research is needed to examine the role of RNA in human disease.”

The new results will allow the immediate development of a genetic test for DM2, and will eventually lead to a more complete understanding and treatment of this form of muscular dystrophy.