When compared to other "'science-based' prediction industries" out there, like functional brain scans, personal genomics tests seem at least marginally useful, writes Daniel MacArthur at Genetic Future. However, he still recommends holding off for a while, untiil we know more about the relationship between gene variants and disease.
A paper published today in PNAS shows that knowing the genetic variants of human enzymes can be very useful, and allow for major improvement with something as simple as vitamins. UC Berkeley researchers sequenced both alleles of the MTHFR enzyme in 564 people and found three common variants and 11 uncommon ones. Yeast follow-up studies showed that adding folate restored full function to the most common variant. "If you don't give people a reason to become interested in their genome and to become comfortable with their personal genomic information, then the benefits of much of the biomedical research, which is indexed to particular genetic states, won't be embraced in a time frame that most people can benefit from," says lead author Jasper Rine in this post at Think Gene.