September 30, 2005

GENOMICS: Genome Scanning Technique Spots Disease Risk Through Sorting Ancestry Mix
A certain genetic inheritance from European ancestors may put African Americans at higher risk of multiple sclerosis, report researchers who used a powerful new way to search for genetic variations associated with disease. The technique, admixture mapping, works only in populations of recently mixed ancestry. It takes advantage of the potentially higher-risk genetic segments from one population that show up in the other. The presence of higher-risk segments in the otherwise lower-risk DNA may reveal common hidden genes that contribute to disease. The study, led by David Reich and reported in the October Nature Genetics, linked MS for the first time with a region on chromosome 1. Because no gene has yet been pinpointed, the researchers are treating their results as promising evidence that the method may be a valuable additional tool to identify new pathways important in disease.

HEALTH CARE QUALITY: Voices Rise Over Surgical Volume–Quality Connection
Does practice necessarily make perfect in surgical care? For more than two decades, evidence has accumulated that hospitals with higher volumes of surgical procedures have better results, and surgeons who perform the most operations have fewer patient deaths. But not everyone believes that more is better. Shukri Khuri and others argue against using what they call an imperfect measure of quality. They are looking for better measures to separate the good hospitals from those that are not so good and encourage data-gathering that will help all hospitals improve their care.

CANCER GENETICS: Studies Chip Away at Sex Hormone Roles in Prostate and Breast Cancers
The protein receptors for androgens and estrogens share a common ability to bind DNA and regulate gene activity, and both are important targets for anticancer therapies. In recent work, Myles Brown and colleagues combined chromatin immunoprecipitation (ChiP) assays with measures of DNA structure and large-scale gene chip analyses to study where, when, and how androgen and estrogen receptors attach to DNA and control gene transcription. Their results should lead to new ways of manipulating receptor activity and shutting down cancer genes while leaving normal genes intact.