Gene
Marker for Longevity Identified:
Mutation
Common Among Centenarians, Study Finds
February 12, 2003; Pasadena, CA (Reuters and MSNBC) – Scientists for
the first time have identified a common genetic mutation in people over 100
years old, a finding they say could be a key to discovering a way to avoid the
ravages of aging. In a study conducted at the California Institute of
Technology, researchers found that centenarians were five times more likely
than others to have the same mutation in their mitochondrial DNA. mtDNA -- the portion of DNA located in the
mitochondria or “energy powerhouses” of the cell – normally passes only from
the Mother to her offspring. The mitochondria capture the energy released from
the oxidation of metabolites and convert it into energy. “It is possible that in the process of
replication these molecules are less damaged by oxidation, but we don’t know
that yet,” said Dr. Giuseppe Attardi, Professor of Molecular Biology at CalTech
in Pasadena, CA and an author of the study.
He said further lab studies are under way to determine the exact
physiological effect of the genetic mutation.
“The key mutation shifts the site at which mitochondrial DNA starts to
replicate, and that may accelerate its replication, allowing the individual to
replace damaged molecules faster,” he said.
In the study of a group of 52 Italian
Centenarians, the researchers found a common mutation in the same main control
region. Looking at mtDNA in white blood cells, they found that 17 percent of
the 52 had a specific mutation called C150T
transition, compared with only 3.4 percent of 117 persons less than the age
of 99. The results are published in the
latest issue of the Proceedings of the
National Academy of Sciences.
To see whether the mutation is inherited, the
team studied skin cells collected from the same individuals between [9 - 19]
years apart. “In some, both samples
showed that the mutation already existed, while in others, it either appeared
or became more abundant during the intervening years. These results suggest
that some people inherit the mutation from their mother, while others acquire
it during their lifetime,” Attardi said.
“The selection of the C150T mutation in Centenarians suggests that it
may promote survival,” he said.
Refs:
1. http://www.msnbc.com/news/8
72441.asp?cp1=1#BODY
2. http://www.msnbc.com/news/H
EALTHPKGS_front.asp