We don't know which of those genes is most likely to harbor this particular risk factor for Alzheimer's disease, but we're getting closer. We're now trying to nail down which one of these six genes is the most likely to be involved.

Most people have a receptor that's very sensitive to the bitter-tasting compound, but in people that have this variant form, they can tolerate higher concentrations of this bitter compound without it tasting nasty to them.

One particular allele of this polymorphism was being transmitted to alcoholics in these families.

We looked in a region of chromosome 7, where there are hundreds of genes, and we noticed that there was a cluster of taste receptor genes in this region.

When we understand more about the genes and the environmental factors that influence someone's risk, I think you will be better able to predict who is at highest risk and then target your prevention strategies at those high-risk individuals.

The region of DNA identified in our study showed evidence of replication in four independent series of experiments. I haven't seen a putative risk factor show such consistent results since the e4 variant of the APOE gene was identified as a risk factor for late-onset Alzheimer's disease more than 10 years ago.