Tag: DNA

Genetic kinship: Who are we and where do we come from?

Valorie Grace HallinanLeave a comment

In My Beautiful Genome, Lone Frank probes her past by having her DNA analyzed for genetic kinship.

State-of-the-art genetic testing can trace ancestry ten or eleven generations back, by looking at a man’s Y-chromosome DNA (which he inherits unchanged from his father) or the mitochondrial-DNA of a man or a women (which they inherit unchanged from their mother.)

Many people interested in genealogy are now supplementing their research with DNA testing of this kind.

Piazza in Carini, Sicily
Piazza in my father’s hometown, Carini, Sicily

As I read about Lone tracing her ancestry, I thought about trips to my father’s birthplace in Sicily I’ve taken with my family. My father was a baby when he crossed the Atlantic Ocean with my grandmother to Ellis Island. I heard the story many times growing up. My grandparents kept in touch with their relatives and returned to Sicily several times to visit.

Because they did, I’ve been able to travel to Carini to meet my father’s family, and my sons have had the opportunity to get to know their Sicilian cousins. That connection with the “old country” is continuing into the next generation, and I hope my children will keep it going with their children.

On our first trip, when we were exploring the cobblestone streets of Carini, we stopped in a bakery. There, we met a man who had my last name (my maiden name.) My family’s surname name is common in Carini.

That day our cousins took us to a nearby castle that had been built around 1075. In the evening we gathered for an elaborate, home-cooked meal at my father’s cousin’s villa in the old section of Carini. Like most Sicilian homes, it is walled off and gated. We sat at several picnic tables end-to-end next to a large, well-tended garden and talked late into the night.

I was steeped in antiquity but surrounded by modernity. Vespas and other traffic passed by outside the garden walls.  I felt a sense of completion. Here were my roots, or half of them, anyway. I looked at the faces of my family and thought about the fact that Sicily has been conquered repeatedly, by the Greeks, Romans, Byzantines, Muslims, Normans, Spanish, and probably others. We have the blood of many races, and who knows what parts of the world our earliest ancestors came from.

I think people are looking for this sense of identity when they do genealogical research and probe their DNA for ancestry. We are, each of us, unique. Yet when it comes down to it, we all come from the same human family.

Have you had your DNA analyzed for ancestry? Are you considering it? If so and you’d like to share your thoughts and experiences, please do in the comments below.

What genetic tests tell us about our health

Valorie Grace Hallinan7 Comments
Chromosome 4
Genome Management Information System, Oak Ridge National Laboratory

I am what I do with the beautiful information that has flowed through millions of years through billions of organisms and has, now, finally been entrusted to me.    Lone Frank

Genetic tests for consumers now cost as little as $99.

Send in a sample of your DNA (usually a swab of saliva) and you’ll be notified of the results by mail, email, or online. (In some states, such as New York, genetic tests must be requested by a physician.)

Science journalist Lone Frank purchased a genetic test kit and sent in her sample of saliva. In My Beautiful Genome, she describes going online and finding out her risk for Alzheimer’s, glaucoma, asthma, gallstones, arteriosclerosis, and other conditions.

Breast cancer is Lone’s number one concern; her mother and maternal grandmother died relatively young from it. At first, she’s relieved, because the test says she has a 7.7 percent risk for breast cancer, lower than a woman’s average risk of 12%.

But when Lone interviews the founder of the genetic testing company, he advises her to get a BRCA gene test because of her family history. Mutations in these genes can mean up to an 80% risk for breast cancer.

When Lone tries to get a BRCA test, she’s turned down, because the testers want evidence of breast cancer in her family going back one more generation, and Lone doesn’t have that information. Nonetheless, she manages to convince them to give her the test.

I’ll permit myself one spoiler and tell you Lone doesn’t have the BRCA genes. She’s tremendously relieved, of course – between that and her lower-than-average 7.7 % risk, maybe the genetic roll-of-the-dice is in her favor.

Not so fast.

The genetic counselor tells Lone that, because both her mother and grandmother died of breast cancer, there could be another risk factor at play – a genetic anomaly for breast cancer that hasn’t been discovered yet.

Let’s say another genetic risk factor for breast cancer comes to light and Lone has it. That would mean her risk rating would increase from 7.7% to something much higher.

The risk ratings from consumer genetic testing are based on limited information, because there is so much we don’t know yet about the human genome and disease. As more of the human genome is decoded, people’s risk ratings change.

The fact of the matter is, every human has over 20,000 genes, and consumer genetic tests examine only a handful of them.

So, just how useful are these tests?

I asked my general practitioner, an excellent physician, what he thinks of direct-to-consumer genetic tests. He’s not enthusiastic.  They yield information that’s incomplete, possibly inaccurate, and worrying. He believes specific genetic tests for specific conditions – the kind of test you’d obtain after a discussion with your health care provider – can be useful, but only if you’re prepared to act on the information. A woman may get a BRCA test, for example, with the intention of having a double mastectomy if the results are not in her favor.

I’m not going to be asking him to request a genetic profile for me anytime soon. When I first began reading My Beautiful Genome, I considered it, but I’m not convinced I’ll learn anything useful, I’ll wonder about accuracy and, depending on the results, I’ll probably worry.

There are lots of other drawbacks, too, which Lone discusses in her book. But she gives equal time to the potential benefits of genetic testing, and writes about what is being done on the cutting edge. Some of what she has to say sounds like science fiction, but it’s really happening.

Lone Frank wants very much to know her own genome; I’ve decided to postpone exploring my own DNA for health reasons until more is known. If and when I do, I’d want to discuss the results with a genetic counselor or other qualified expert.

Still, I’m excited about the prospect of someday knowing something about my own genetic code. I hope that day isn’t too far away.

And if I ever have the opportunity to participate in a research study about the genetics of something I care about – schizophrenia, for example – I’d volunteer in a heartbeat.

Would you choose to explore your DNA with a genetic test? Have you already been tested? What do you think of consumer genetic tests? Please share your thoughts in the comments below.

Would I have my DNA analyzed for ancestry? That’s another story. In my next and last post about My Beautiful Genome, I’ll write about what Lone learned about her genetic roots.

Do genes shape our mental health?

Valorie Grace Hallinan1 Comment

mybeautifulgenome

“I want to know what it feels like to have a close encounter with my DNA, this invisible, digital self that lies curled up like a fetus in every single cell of my body.”  – Lone Frank

When asked by the researcher if she has first-degree relatives with mental health problems, Lone Frank says yes.

Asked which ones, Lone says: all of them.

Depression, multiple suicides, bipolar disorder, alcoholism. With mordant humor, Lone Frank describes her family history. She’s forthcoming about her own three episodes of depression, then lies to the researcher about how many drinks she has each week. Fourteen glasses of red wine, for the health benefits. (But it’s really closer to twenty drinks or more. At least, that’s what she tells the reader.)

Lone, a Danish science journalist with a PH.D. in neurobiology, volunteered to take part in a major research project to study the connection between personality, an inclination toward depression, and specific genes.

In My Beautiful Genome: Exploring My Genetic Future One Quirk at a Time, she takes us along as she undergoes genetic testing, completes questionnaires and personality tests, and talks with multiple experts who interpret the results. Along the way she grapples with many questions.

Does she, indeed, have genes that predispose her to depression?

How does the environment factor in, as well as her upbringing and her own free will to pull herself out of depression and make cognitive and lifestyle changes to prevent it?

Does she unwittingly contribute to her own dark moods and temperament by building her own, unique environment – under the influence of her genes – that is conducive to depression?

On the other hand, does she possess certain genes or genetic variations that give rise to traits that help her excel in certain areas?

Chromosome 2
Chromosome 2 (click twice for larger image)
Genome Management Information System, Oak Ridge National Laboratory
Human Chromosomes from “Human Genome Landmarks: Selected Genes, Traits, and Disorders” Poster, 2002. (Gene Gateway)

Do some genetic variations mitigate the effects of others?

Are there “good” and “bad,” “healthy” and “unhealthy” genetic variations, or simply variations that lead to different outcomes depending on one’s circumstances?

I won’t give away what Lone discovers, but she finds out a lot and, in the end, concludes the information is enormously helpful.

Let me stress that the average lay person could not mine their own genome for this information the way Lone did. Because she’s a journalist with a doctorate in neurobiology, she had access to sophisticated genetic tests and, more importantly, to experts who could interpret the results and how they might affect her personality and behavior.

Nonetheless, mining Lone’s genome with her is a glimpse into what may be possible for all of us, eventually, if we want it.

How much would you want to know about your genes and how they might shape your personality and behavior? Please share your thoughts in the comments.

Coming up, what Lone’s DNA reveals about her future health.

Quote from My Beautiful Genome: Exploring My Genetic Future One Gene at a Time, by Lone Frank, Oneworld Publications, Oxford, 2011.

Meeting the dark matter of mental illness

Valorie Grace Hallinan7 Comments

mybeautifulgenome

In the first pages of Lone Frank’s My Beautiful Genome, I discovered that what has always been a mystery is indeed still a mystery.

In a previous post, I talked about my mother’s schizophrenia, and how that had been a factor in whether or not my husband and I would have children.

Chromosome 1
Chromosome 1 (click for larger image)
Genome Management Information System, Oak Ridge National Laboratory
Human Chromosomes from “Human Genome Landmarks: Selected Genes, Traits, and Disorders” Poster, 2002. (Gene Gateway)

Lone tracked down the curmudgeonly and controversial James Watson (who, with Francis Crick, discovered the chemical structure of DNA in 1953) and, among other things, they discussed the heritability of schizophrenia.  Watson’s son has schizophrenia.

After several major studies involving some 50,000 patients, next to nothing is known about the heritability of schizophrenia.

No particular genes were found to be associated with schizophrenia (except in a very small percentage of cases), and the few genetic links found were not the same genes in all patients.

This is known as missing heritability. Lone Frank calls it the “dark matter” of the genome.

Watson and others theorize that the cause of schizophrenia and other diseases and conditions for which there is no obvious genetic inheritance may be due to rare variants – genetic changes not inherited from the parents, but which occur spontaneously in the afflicted person.

With a kind of despair, Watson said it may be ten years before the genetics behind serious psychiatric illness is better understood. This knowledge won’t help his son, of course. But, as Watson says, many people are suffering.

I would like to see the suffering of schizophrenia end, too.

Of course, Watson is a scientist, and he wants to know. So do I. Ten years doesn’t sound long to me, considering I’ve been living with this mystery for nearly fifty years.

This may be an illusion, but if I could better understand the dark matter of my mother’s life, perhaps it would be a comfort. We all want to make sense of our suffering.

I think My Beautiful Genome may be one of the most important books I’ll ever read in my adult life. For me, it’s personal, but it’s personal for all of us.  Genetics is giving us (and our children) powerful information humans have never had before.

Do you want to know what the new genetics could mean for your future health or the health of your children and grandchildren? What can genetics tell us about mental illness? How will knowing our own genome influence our romantic relationships and how we choose the person with whom we’ll have children?

Lone Frank wanted to know the answers to these and other questions. In future posts, I’ll tell you a little bit about what she found out.

Exploring Genetics 

Check out Cold Spring Harbor Laboratory’s DNA Learning Center.