Talk

The NY Times reported today about a genetic study that helps to confirm anthropological theories about the ancestral origins of the people living on the widely scattered Pacific Islands:

In an analysis of the DNA of 1,000 individuals from 41 Pacific populations, an international team of scientists found strong evidence showing that Polynesians and Micronesians in the central and eastern islands had almost no genetic relationship to Melanesians, in the western islands like Papua New Guinea and the Bismarck and Solomons archipelagos. …

The new genetic research, said Patrick V. Kirch, an anthropologist at the University of California, Berkeley, who is an authority on Pacific cultures, was “overwhelming biological evidence for a clear population movement out of Southeast Asia and Taiwan to Polynesia.” (more…)

Stalking Strangers’ DNA to Fill in the Family Tree: How far would you go to find out about distant relatives and common ancestry with strangers? Many of the situations described here seem a little, shall we say, outside the bounds of propriety and into the realm of CSI. Have we all been watching too much crime TV?

ACS Recommends Regular Breast MRIs for Women at High-Risk for Breast Cancer: Listen to Elizabeth Morris from Memorial Sloan Kettering discuss the new guidelines on NPR’s “Science Friday with Ira Flato“. Women should consider annual MRIs if they’ve got a strong family history, if they’re a BRCA mutation carrier, if they’ve had chest radiation treatments for conditions such as Hodgkin’s Disease. As a caller on this program points out, recommendations are inevitably two steps ahead of the medical establishment and insurance coverage. If you’re interested in pursuing MRIs, head to the big cities and major medical centers for radiologists who can perform and accurately read these MRIs. Now, to call my doc for a referral for an MRI…. (Update: Check out Emily DeVoto’s Antidote for counterspin on these recs.)

Chimeras: A New Kind of Twin: For the first time, researchers have identified twins that are identical on their mother’s side (same egg), but share only half of their father’s DNA (different sperm). Dr. Vivienne Souter, lead investigator in the journal article reporting this finding, says that while the term semi-identical provides some idea of how the twinning occurred, it is “an oversimplification.” I’ll bet! But I can’t wait to hear more.

Technorati Tags: ancestry, nonpaternal events, dna testing, family tree, genealogy, medical guidelines, american cancer society, breast cancer, MRIs, screening, high risk, genetic chimera, twins, genetics, intersex, hermaphrodite

At a baby shower this weekend, I had one of my two regular party conversations. Someone says, “Genetic testing? Cool! Do you do all that CSI stuff?”

No, I don’t wield big flashlights and hang around crime scenes. DNA can tell more than one interesting story. In addition to forensics, DNA technology is used for…

Predispositional Tests. These tests can give you permanent, life-long insight. They look at your genetic makeup to see if you carry a gene that puts you at higher risk for a certain disease. This type of testing can also be used to confirm a diagnosis, or determine whether a condition you already have is genetically based.

Screening Tests. Similar to X-rays or other tests that record a moment in time, these tests look at a cell sample for “acquired” DNA mutations (not inherited) that can indicate whether a disease, such as cancer, is present in a part of the body.

Paternity Tests. This type of testing looks at the DNA of a mother, child, and the man thought to be the child’s father, to see if the man is indeed the biological father of the child.

Ancestry Tests. These tests look at your Y chromosome (men only) and mitochrondrial DNA for specific genetic markers that are unique to certain populations. These markers indicate your deep ancestry migration patterns, and thus, genetic ethnicity. (Have I raved about the Genographic Project yet?)

Drug Metabolism Tests. These tests tell you how quickly your body processes certain types off drugs, and whether or not you are likely to experience side effects or toxicity. For some drugs, testing will tell you whether the drug in question will be effective.

So what’s the other party question? “Can you test my dog to see what breeds he’s made of?” (No, not yet :-))

In an article entitled “Missing Links” (WSJ), Donald Moffitt explores how DNA testing has become the new trend in genealogy. He writes:

“DNA Testing has the hottest tool in geneaology, allowing amateur slueths like myself to graft and prune their family trees. The process is simple, involving little more than a swab of the inside of your cheek. Advances in lab technology, meanwhile, have brought the costs down to home-appliance levels. And for your efforts, you can learn, among other things, some of the ancient ethnic and geographic origins of your ancestry. But beware: DNA can open doors you can’t close.”

Moffitt relates his own interesting story. Testing in his family uncovered a new branch on the family tree and a mysterious stranger by the name of Rutherford, who could “almost be a genetic brother.”

“The tests first showed that all of us shared a straight paternal-line ancestor, perhaps with 100 million or more males in Wester Europe and the Americas. The patriarch seems to have fathered a Stone Age clan in northern Spain that survived, grew and drifted northward as the glaciers of the Ice Age began to melt…. But our tests also showed that the four of us shared an extrememly rare mutation along the Y chromosome, a DNA pattern that appears in only a few hundredths of 1% of the R1b population. That match…was a virtual guarantee of close kinship.”

DNA insights in hand, Moffitt’s historical research takes him back to colonial Virginia, where he eventually finds…drumroll…a Moffitt and a Rutherford who are neighbors. The rest? Well, that must be left to conjecture.

You can see the map of my haplogroup (R1b M343) at the Personal Genome

Technorati Tags: genes, ancestry, genetic testing, geneaology, haplogroup, R1b, M343

The advent and increasing popularity of ancestry testing raises complicated issues about how we conceive of ethnicity, and what it means to claim it — Is ethnicity genetic? Is it cultural? Is it how you see yourself, or how the world sees you?

Today’s New York Times (“Seeking Ancestry in DNA Ties Uncovered by Tests”) discusses how people are using, and wrestling with, the increasing popularity of this testing. (Disclosure: our company, DNA Direct, does not do ancestry testing. We stick to tests with health/medical applications).

Like the expression of genes themselves, our understanding of “race” and “ethnicity” is dynamic: It will continue to evolve, it will be complex, it will be individual, and it will be influenced by many environmental, personal, and genetic forces.

Technorati Tags: ancestry, DNA testing, genes, genetics, ethnicity