http://www.sciencedaily.com/releases/2008/06/080624174849.htm
Our Genome Changes Over Lifetime, And May Explain Many 'Late-onset' Diseases
ScienceDaily (June 25, 2008) —

Researchers at Johns Hopkins have found that epigenetic marks on DNA-chemical marks other than the DNA sequence-do indeed change
over a person's lifetime, and that the degree of change is similar among family members. The team suggests that overall genome
health is heritable and that epigenetic changes occurring over one's lifetime may explain why disease susceptibility increases with
age.

"We're beginning to see that epigenetics stands at the center of modern medicine because epigenetic changes, unlike DNA sequence
which is the same in every cell, can occur as a result of dietary and other environmental exposure," says Andrew P. Feinberg, M.D.,
M.P.H, a professor of molecular biology and genetics and director of the Epigenetics Center at the Johns Hopkins School of Medicine.
"Epigenetics might very well play a role in diseases like diabetes, autism and cancer."

If epigenetics does contribute to such diseases through interaction with environment or aging, says Feinberg, a person's epigenetic
marks would change over time. So his team embarked on an international collaboration to see if that was true. They focused on
methylation-one particular type of epigenetic mark, where chemical methyl groups are attached to DNA.

"Inappropriate methylation levels can contribute to disease-too much might turn necessary genes off, too little might turn genes on
at the wrong time or in the wrong cell," says Vilmundur Gudnason, MD, PhD, professor of cardiovascular genetics at the University of
Iceland director of the Icelandic Heart Association's Heart Preventive Clinic and Research Institute. "Methylation levels can vary
subtly from one person to the next, so the best way to get a handle on significant changes is to study the same individuals over
time."