Medicine gets personal: Will genetic profiles change health care?

Biomedical researchers are getting personal. That, at least, is the trend foreseen by geneticist T. Conrad Gilliam of the University of Chicago, who spoke on 13 February at the AAAS meeting in Chicago. In a provocative address titled "Human Genetics, Genomics, and the Future of Medicine," Gilliam explored personalized medicine — and his efforts to trace some diseases to many sets of interacting genes.

Personalized medicine entails using molecular analysis to better understand and manage human disease. The approach, Gilliam said, may allow physicians to use a patient's genetic profile to customize medical care. His goal is to "tailor" medical treatments by identifying DNA sequence variants involved in the expression of certain diseases.

"If we can predict the multigene pattern of inheritance that shows you're susceptible to asthma and then find the environmental triggers that go with that pattern, we could start to help in a preventative way to treat asthma," said Gilliam.

During his talk, Gilliam explained how current understanding of diseases such as autism and macular degeneration may be enhanced by exploring the underlying interactions of genes. One's susceptibility to disease often arises from multiple mutations on multiple genes, not a single mutation on a single gene, he noted. Pinpointing the location of these genes is a main focus of Gilliam's research.

"I think the most daunting challenge, but not the only one for the development of personalized medicine, is the identification of these multigene patterns of inheritance that correlate with disease liability," said Gilliam. "All bets are that the common disorders have a multigene etiology. I suspect that it's true for asthma, migraines, schizophrenia, and so forth."

Gilliam's research may help redefine the existing perception of certain neurologic diseases. For example, many investigators believe autism is caused only by multiple variants of a single gene, but Gilliam thinks other interactions may be taking place.

"It's clear that it's not just a single gene," said Gilliam. "Maybe some portion of all autistic patients have a single gene etiology, but it's quite clear that at least some other portion is multigene, and I suspect most are multigene."

During his research, Gilliam collaborated with Andrey Rzhetsky, a biomedical informatics expert at Columbia University, to create a map of biologically relevant gene interactions. This map was used to reduce the search space of genes. The program that created the map is one of the first of its kind. It composed genetic pathways from information that was published in electronic journal articles. This allowed Gilliam to narrow his search for relevant genes.

"We wanted to use these gene networks to guide the search for novel disease genes when one or more candidates are known," said Gilliam. "The idea is that we are going drop in a few genes that we know are disease genes, and we are going to ask it to find its partners and see if those genes are new disease genes."

Gilliam's approach to deciphering gene networks is one technique that can be used to help explain underlying gene interactions and their correlation to diseases. The accurate identification of the DNA variants associated with common diseases would give rise to personalized medicine, an approach that promises to refine the healing arts in novel and far-reaching ways.

#

Brent M. Ardaugh is a medical writer and editor from Purdue University in West Lafayette, IN. Reach him at bardaugh@purdue.edu