For many diseases, there is no way to identify which embryos carry the disease genes.

"It shows there are more ways to find a disease gene than to simply apply the standard gene-mapping approaches."

This study was successful in uncovering many new disease genes underlying these diseases.

Possible early applications, however, might be closer to eliminating disease genes passed on to children.

Why do certain disease genes seem to affect or "penetrate" some people more than others?

She was one of the group who first cloned the Huntington's disease gene.

The task of searching for disease genes is expected to be performed by the Iceland project and its rivals.

When the research hits its mark, and a disease gene is finally found, it adds a single, small piece to a profound puzzle.

"There have not been too many disease genes found with the existing tools," he said.

The goal of the hapmap is not to find disease genes directly but to create a general tool that will allow others to do so.