Washington, June 3 : Scientists at the University of California, Berkeley, predict that people's personal genomes will be tested in future to detect any slight genetic flaws that can be fixed with remedies as simple as vitamin or mineral supplementation.
"I'm looking for the good news in the human genome," said Jasper Rine, UC Berkeley professor of molecular and cell biology.
"Headlines for the last 20 years have really been about the triumph of biomedical research in finding disease genes, which is biologically interesting, genetically important and frightening to people who get this information. I became obsessed with trying to decide if there is some other class of information that will make people want to look at their genome sequence," he added.
In an article published in the online edition of the journal Proceedings of the National Academy of Sciences (PNAS), Rine and his colleagues have said that there are many genetic differences that make people's enzymes less efficient than normal.
The researchers say that simple supplementation with vitamins may help restore some of such deficient enzymes to full working order.
Nicholas Marini, a UC Berkeley research scientist who is the first author of the study, says that doctors usually recommend vitamins to treat many rare and potentially fatal metabolic defects that are caused by mutations in critical enzymes.
He, however, points out that people with such metabolic diseases generally have two bad copies of an essential enzyme.
According to him, there may be people having only one bad gene or two copies of slightly defective genes, which have thrown their enzyme levels off slightly and caused subtle effects that may be cured with vitamin supplements.
"Our studies have convinced us that there is a lot of variation in the population in these enzymes, and a lot of it affects function, and a lot of it is responsive to vitamins. I wouldn't be surprised if everybody is going to require a different optimal dose of vitamins based on their genetic makeup, based upon the kind of variance they are harboring in vitamin-dependent enzymes," Marini said.
The researchers have revealed that they have tested the function of human gene variants by transplanting them into yeast cells, where the function of the variants can be accurately assessed, and they are confident that the results will hold up in humans.
Rine and Marini say that they are contemplating employing US soldiers to test whether vitamin supplementation can tune up defective enzymes.
"Our soldiers, like top athletes, operate under extreme conditions that may well be limited by their physiology. We're now working with the defense department to identify variants of enzymes that are remediable, and ultimately hope to identify troops that have these variants and test whether performance can be enhanced by appropriate supplementation," Rine said.
The researchers reckon that the average person has five rare mutant enzymes, and perhaps other not-so-rare variants, that can be improved with vitamin or mineral supplements.
They have so far analysed variants of only one human enzyme called methylenetetrahydrofolate reductase (MTHFR).
They are continuing to study variation in the human MTHFR gene and other folate utilizing enzymes, particularly with respect to how defects in these enzymes may lead to birth defects.
One of their aims is to find out how vitamins and minerals fix defective enzymes.