University page

Scientists at The University of Texas Health Science Center at San Antonio played a major role in the recent discovery of important genetic information related to muscular dystrophy.

University of Minnesota researchers called the Health Science Center, the world's repository for chromosome 3, for assistance with a study published today in the international journal Science.

"We helped them discover all the genes in the region they had identified as the location of the myotonic dystrophy gene," said Susan L. Naylor, Ph.D., who led the Health Science Center's participation in the worldwide Human Genome Project. "It is an example of the international collaboration that is needed to implement the data from the Human Genome Project."

Dr. Naylor and her staff contributed to the findings of an expanded sequence repeat on chromosome 3 as the cause of a myotonic dystrophy called DM2. The disease is a type of muscular dystrophy similar to, but genetically distinct from, myotonic dystrophy 1, or DM1. DM1, the most common form of muscular dystrophy in adults, results from an expansion of a genetic sequence repeat on chromosome 19.

"On average, this expansion repeats 5,000 times. We don't see an expansion in chromosomes of people without the disease," Dr. Naylor said. "In both chromosomes 3 and 19, expansion happens outside the gene's coding region. We suspect it interferes with production of crucial proteins. When there is a deficient supply of these proteins, muscular dystrophy occurs."

The Health Science Center, in collaboration with other centers, played a significant role in ensuring that chromosome 3 was "sequenced" - that the order of the genetic material in the chromosome was precisely revealed and catalogued. Chromosome 3, the third-largest human chromosome, accounts for 7 percent of a person's genetic blueprint. Increased knowledge of the genome is changing the face of disease prevention, diagnosis and treatment.

Contact: Aileen Salinas or Will Sansom