Gene Family for cancer discovered
BY STUDYING the genetic profiles of siblings who lived to extreme old age, researchers at Beth Israel Deaconess Medical Center in Boston said they have found subtle differences in gene structure that may be responsible for their living into their 90s and beyond.
Dr. Thomas Perls, a co-author of the study, said the next step is to isolate the specific gene or genes that are unique to people who lived to extreme old age.
If such genes are found, said Perls, it may be possible to develop therapies that will help slow the rate of aging, just as occurred naturally in the centenarians his group has studied.
"We’re not trying to find the fountain of youth," said Perls. "We’re trying to find the fountain of aging well."
One in 10,000 Americans is a centenarian, living about 20 years past the average life span. Despite their rarity, centenarians are the fastest growing segment of the U.S. population, according to Perls.
Perls said the section of chromosome 4 isolated by the researchers contains 100 to 500 genes and it is not clear yet which or how many of these genes are related to long life. Perls said genes on other chromosomes also may be involved.
Study details
The key chromosome section was found by studying the gene structure from 137 sibling groups that had demonstrated the family trait of long life. At least one member of each sibling group had reached the age of 100 or more, and the brother or sister had to be age 91 or more. The study group included 308 people with ages ranging from 91 to 109.
Blood samples were obtained from each of the study subjects and the genetic structures were compared to find genes that might relate to aging. The search led them to a region on chromosome 4 that contains between 100 to 500 genes. Perls said they are 95 percent certain that area is the right section.
Perls said it is possible that people who inherit the trait of living to be 100 years may have "the ideal human genome" or gene structure. He said ordinary genes and good health habits can provide a normal lifetime of 80 or so, but there may be unique genes that allow people to live to an extremely old age.
The study appears in the Proceedings of the National Academy of Sciences.
THE SEARCH CONTINUES
Co-author Louis Kunkel of Children’s Hospital in Boston said the researchers hope to find the precise gene or genes responsible for long life within six months to a year. He said a subtle genetic variation - called a single nucleotide polymorphism - appears to be at work, rather than a genetic mistake like those that cause hereditary diseases.
Asked what exactly a longevity gene might be doing to add decades to a person’s life span, Kunkel admitted, "We don’t have a clue at the moment."
The Associated Press and Reuters contributed to this report.