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Wednesday, January 10, 2018

Exploring Your DNA

The DNA Double Helix
The DNA Double Helix
Curiosity can be a dangerous thing. Especially when it may give unsettling answers. Here is what happened when I ventured into the new science of genetics.

Shortly after I retired in 2011, I found myself a patient at Suburban Hospital in Bethesda recovering from a minor medical episode. A representative of NIH visited me and asked if I would like to participate in a DNA study called Clinseq. The goal is to identify genetic markers linked to particular diseases and conditions. I was excited to learn I could contribute to medical research in this way. All I had to do was provide a blood sample and fill out detailed questionnaires about my own and my family’s medical history. I receive regular updates, first informing me that my DNA had been sequenced, and then letting me know about any identified markers found. The study is also concerned with how people react to receiving genetic medical information. Does this knowledge empower or cause anxiety? So after each revelation I answer an online questionnaire about my reactions. Thankfully, nothing alarming has turned up so far.

DNA Double Helix with Base PairsMore recently I decided to have my DNA tested by Ancestry.com. Yes, I finally succumbed to those ubiquitous ads with the guy wearing lederhosen who finds out he should really be wearing a kilt. Am I really half Irish and half Flemish as I supposed, or were the family rumors, on both sides, that we had Spanish blood, true? The rumors turned out to be false, but I was completely shocked to find out that the greatest proportion of my DNA is from England, where I grew up, even though I am the first generation born there. How can this be? So far, I have learned that Dutch and Flemish DNA is very like that of south-east England, reflecting the history of close relations between the countries, and is therefore often mistaken for English. On the positive side, the test did accurately pinpoint the precise area of Ireland my ancestors are from. Disappointingly, unlike many Irish, I am not the product of a long-ago Viking raid.

Both these personal journeys into the science of DNA would have been completely unimaginable just a few decades ago. The discovery of the structure of DNA in 1953 and then the sequencing of the human genome completed in 2003 have revolutionized medicine, the study of human history, and the personal search for family roots.

These resources explain the science of the discoveries and their medical applications:

The classic account of Watson and Francis Crick’s scientific breakthrough. The book omits, however, any mention of Rosalind Franklin’s contribution to the discovery. As a woman scientist, her work was devalued at the time and she did not share in the 1962 Nobel Prize awarded to the men.

This biography gives Franklin her rightful place in science history.

The most complete resource about the Human Genome Project is on the NIH website. The National Human Genome Research Institute led the American contribution to this international project. Here you can find an interactive timeline of human genome research and a wealth of information for understanding the science of genetics, its uses, and implications for the future.

An introduction to the cutting edge of medicine and the ethical dilemmas it poses.

Several recent books cover new discoveries in human evolution and prehistory:

A good overview of how DNA has changed our understanding of the origins of modern humans.

How geneticists “have blown the lid off what we thought we knew” about 100,000 years of human history, including how humans settled North America.

An account of the National Geographic Project, the study of the largest collection of DNA samples in the world, and what it tells us about the human family.

The Swedish journalist’s quest for her own family roots, tracing her mitochondrial DNA, passed on through the female line, back to the earliest humans in Europe before the Ice Age.

The Neanderthal genome was sequenced in 2009, leading to one of the more startling discoveries of genetic history. Humans and Neanderthals interbred and many modern humans carry Neanderthal genes in their DNA.

Book cover for the Last NeanderthalFinally, there is a wonderful fictional imagining of the time when Neanderthals and early humans shared the earth. The Last Neanderthal by Claire Cameron is in the tradition of Jean Auel’s Clan of the Cave Bear (Earth's Children) series. Beautifully written and emotionally powerful, it is the story of a young pregnant Neanderthal at the time that her people are disappearing.

My own foray into personal genetic research still leaves me with many unanswered questions. I shared my results with my cousins in Belgium to see what they thought about possibly being part English. I heard back from one of the younger generation. He told me he is currently spending a year as a visiting researcher at the University of York in England. His field? Archaeogenetics. He sent me rather an intimidating reading list of scholarly books and articles.

Rita T.
Rita T.

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