DNA Spells Future of Medicine, Genetics Expert Says at Northwestern


A purified DNA, fluorescing orange under UV light, being extracted with a syringe and used for molecular biology studies. Mike Mitchell/NATIONAL CANCER INSTITUTE

Personal genome sequencing could potentially offer a novel treatment for cancer, make medications work better and help prevent people from getting diseases.

The technology - also known as whole genome sequencing - was the stuff of a promising future Wednesday night when Dr. Marc S. Williams, a genetics expert, lectured to nearly 200 people at Northwestern University's Evanston campus about the possible medical advances within their own bodies.

"It's extraordinarily exciting and extraordinarily frightening to think about how much there is to learn," said Williams, the director of the Geisinger Health System Genomic Medicine Institute in Danville, Penn., in an interview prior to his lecture. "We're just beginning to scratch the surface of our understanding."

Dr. Marc S. Williams talks about personal genome sequencing at a lecture Wednesday night at Northwestern Unoversity in Evanston. Lyz Hoffman/MEDILLDr. Marc S. Williams talks about personal genome sequencing at a lecture Wednesday night at Northwestern Unoversity in Evanston. Lyz Hoffman/MEDILL

What Williams and his colleagues do know, he said, is that there are more than 6 billion letters in every person's two strands of DNA. Whole genomic sequencing, therefore, means identifying and then understanding each of those letters.

"That's really the easy part, believe it or not," Williams said. "The hard part is that information is really of no use unless we can somehow understand what each of those letters or differences in letters means for the person. We want to be able to take out that specific information, which is a tiny fraction of the 6 billion letters, and use that to improve people's health."

The challenges in getting to that point, Williams said, are threefold: annotating of all of the letters, interpreting what the letters represent and then applying that information in a "medically relevant" way to patients.

The process works like this: a person submits cells from their body (from blood, spit or skin), DNA is extracted from those cells and then the DNA molecules are put into a machine that spells out all of the letters. Williams said that not all of the 6 billion letters will be medically important, but the ones that, for example, could reveal information about a person's ability to metabolize drugs, would be filtered out and further analyzed.

Over the course of a person's life - from infancy to adulthood - whole genome sequencing could play a pivotal role in treating existing illnesses and preventing new ones from developing, Williams said. Newborns could be screened for immunodeficiency problems, teens for adult-onset disorders and adults for preventative treatments.

"I think it's exciting," said Laurie Rubin, a Winnetka homemaker who attended the lecture.

Jessica Gu, a Northwestern University graduate student studying genetic counseling, said she thinks "it's inevitable that medicine will go this way."

While Williams said the therapies could be initially more costly, that challenges lie ahead in how the information would be stored and made accessible and in how the information would be used, he said he is looking forward to the discovery process.

"It's really exciting to be able to be a part of it," he said.  


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