There are a lot of good reasons not to have sex with your cousin, but probably the best reason is that you put your potential offspring at a higher risk of inheriting a genetic disease. I know this because I spend a lot of time at genetics conferences. These events are always fun – you get to see old friends and drink wine and eat stuffed mushrooms and listen to talks about the genetics of different forms of cancer.
The liveliest sessions though concern what the geneticists politely call “consangunity” – the sharing of blood, the state of being inbred. This is actually a big headache for clinicians. They run the child’s sample to identify the genetic variant that might be causing the disease, and then they run samples from both parents to see if they also carry the variant. Then, to their surprise, they discover that significant blocks of the child’s genome and the parents’ genomes are the same. A child born of an incestuous relationship, say between a father and daughter or a brother and sister or a mother and son, may carry 25 percent of the same genome as the parent. This, the geneticists say so politely, is an example of “consanguinity in the first degree.”
Watching all these presentations about incest gets me thinking about my Estonian friends. How come so many of them look the same? And, more importantly, how do they know that they aren’t related? Especially today, when so many children are born out of wedlock, it is entirely possible that some randy wayfarer could father a child in Pärnu and one in Jõhvi and they would grow up and have a midnight tryst in a parking lot somewhere in Paide and unwittingly have a kid with a genetic disorder.
I ran my suspicion of Estonian inbreeding by my friends Enn and Kaari, but was rebuffed when I insinuated that it was possible that they might be related. They know they are not closely related said Kaari, because they had genetic ancestral testing done. At the time, there were two main tests for ancestry in the market. Men can have their Y chromosome tested: tracing their paternal line back, as well as their mitochondrial DNA tested, tracing their maternal line back. Women, having no Y chromosome, can only trace their maternal line back. According to their test results, Enn’s forefathers apparently got to Estonia by way of India, while Kaari’s mtDNA was found in highest percentages in Sami women. They weren’t related afterall. See, Enn is actually Hindu and Kaari is actually Sami. Viljandi is a diverse town!
I have always been a little proud that there is little chance that Epp and I are related. Some people are proud of being all one thing, but my kids count among their ancestors Estonians, Italians, Irish, Scots, Russians, English, Germans, Dutch, Greeks and Albanians. Sometimes, when my father drinks his coffee and gets excited, he starts adding others to the list. “You know, my German great grandfather came from a town on the Czech border,” he says. “We could be Czech!” He says it as if I should go out and buy a six-pack of pilsner and place a framed picture of Vaclav Havel on the shelf.
Needless to say, no one can say what nationality my children most resemble. One of our friends, a world traveler, says that it is impossible to say what they look like. “Your kids are like an earthworm crossed with a rhinoceros,” he says. Still, after hearing Enn and Kaari’s story, I decided that we should also get tested, if only to have something to talk about in their cafe. I tested my Y chromosome first, tracing my forefathers back to the beginnings of time. These men were from southern Italy, so I thought that the results would show a migration through Greece or Turkey. Or maybe even Africa! Wouldn’t it be terrific, I thought, to discover that I was actually black? Perhaps it would explain my love of African music.
Instead, my forefathers apparently came from northern Italy, southern France, or northern Spain, where the same results are found in the highest percentages. I do have a geneticist friend named Ernesto whose family comes from northern Spain and I have always noticed how we have a similar appearance. At last, I had an explanation! We descended from the same dark-haired, spear-chucking barbarian. Then I ordered Epp’s mtDNA test. Her friend, the same world traveler, has seen a photo of Epp’s grandmother and insists that she is Jewish. It’s in the curly hair, the eyes, and, most of all, the nose, he says. This friend is from the same part of Estonia on the west coast, and tells tale of a caravan of Jewish families who settled long ago north of Pärnu and over time became Estonians.
When asked about it, Epp’s grandmother said she had never heard of such a thing, and expressed a general disinterest in our modern genetic adventure, but Epp remained very excited by the idea that she could be Jewish. While waiting for Epp’s results, I took long walks near Viljandi Lake and pondered what the discovery of my wife’s Jewish ancestry would mean for our family. Would I have to familiarize myself with the Torah? Start eating unleavened breads? Could we still celebrate Christmas? Maybe it would be good for us, I thought, because once Stephen Spielberg found out you could count on seeing My Estonia the movie in every theater in the world, starring Adrian Brody and Natalie Portman.
But, alas, Epp had the same results as Kaari, a maternal lineage suggesting an origin in Finnic populations and found at its highest percentage in the Sami. We were confused. What about the Jewish settlers in Pärnu? But Kaari was very pleased to know that she and Epp both descended from the same little Sami woman.”You know, I always knew you were Sami,” Kaari said putting an arm around my wife. “You did?” Epp said. “Of course,” said Kaari. “You look just like one!”