DNA sequenced of woman who lived to 115

The entire DNA sequence of a woman who lived to 115 has been pieced together by scientists, BBC News reported.

The woman, who was the oldest in the world at the time of her death, had the mind of someone decades younger and no signs of dementia, Dutch experts said.

The study, reported at a scientific conference in Canada, suggested that she had genes that protected against dementia.
Further work could give clues to why some people are born with genes for a long life, according to a UK scientist.

It is more than 10 years since the first draft of the human genetic code was revealed.

Since then, perhaps a few hundred individuals have had their genes mapped in full, as the technology to "read" DNA gets better and cheaper.

The woman, whose identity is being kept secret, and is known only as W115, is the oldest person to have her genes mapped.
She donated her body to medical science, allowing doctors to study her brain and other organs, as well as her entire genetic code.
Dr Henne Holstege, of the Department of Clinical Genetics at the VU University Medical Center in Amsterdam, said she appeared to have some rare genetic changes in her DNA.

It is not yet clear what role they carry out, but it appears there is something in her genes that protects against dementia and other diseases of later life.

Dr Holstege told the BBC: "We know that she's special, we know that her brain had absolutely no signs of Alzheimer's.

"There must be something in her body that is protective against dementia.

"We think that there are genes that may ensure a long life and be protective against Alzheimer's."