Thursday, April 23, 2009


Ça c’est un nom bien de chez nous!” – That’s a typical Alsatian name! This was the answer given to me some years ago by an Alsatian gentleman, to whom I was speaking on the phone, when I offered to spell “Gerschenfeld”. I was stupefied: for the first time in my life, someone was telling me my surname sounded typical to him.

On the contrary, I’d gotten used – then in France and now also in Portugal – to remarks such as “ouch, what a complicated name!”, or “that’s a foreign name, isn’t it?”. Or even worse, to phonetic deformations of my patronym that go beyond what one might reasonably expect (“Mme Chantapel? I’m calling you about…” – that was the beginning of another unforgettable phone call, also in French).

For those who have always known their surnames were “typical” of some place, wherever that might be, my reaction may seem strange. But believe me: I was utterly surprised and delighted by that (immediately) nice Alsatian man’s reaction. My name, I realized, might be from somewhere after all…

Five years after his death in Paris, my father’s memoirs have just been published by Libros del Zorzal Editions, under the title Autobombo (which means something like “showing off”), in Argentina, where he had emigrated from Poland with his family when he was only six months old. And as I reread the book, I discovered a historical explanation for the spontaneous familiarity that gentleman from Alsatia had expressed with regard to surnames like mine.

My paternal and maternal surnames [Gerschenfeld and Rosenblatt], my father writes, make me think that my family came from Alsatia or Rhenany, were Jews had settled in the fourteenth century, after their exclusion from France and England. A further series of expulsions forced them to move eastward, to other regions of Germany, and in the fifteenth and sixteenth centuries, they finally settled in what was then the Kingdom of Poland (which also included parts of Ukraine).
At that time, Jews were not allowed to reside in the Empire of the Tsars, but after several partitions of the Kingdom of Poland, between 1772 and 1795, more than 70 percent of that kingdom’s territories had been annexed by the Russian Empire. In this way, and since Catherine the Great imposed on them to remain in the so-called “reserved zone” (in Russian,
Cherta Osedlosti), those Jews automatically became the discriminated subjects of that empire, which spanned territories that are today part of Poland, Lithuania, Ukraine, Romania, and Belarus.
Pages of the book, written in Spanish, containing this excerpt

So this explains that… And it also explains why, when I looked more closely at the genetic similarity map 23andme had constructed based on the results of my DNA test (which I have already written about in this blog), I realized that, although the “Ukrainians” are, as I already mentioned, the population whose genetic makeup is closest to mine, that map places me, in fact, at the confluence of people from all over Europe – and in particular of Northern Europe, which includes the French and the Germans.

On the other hand, I’m also very close to the Austrians – and, from Southern Europe, to the Italians –, which suggests that my ancestor’s trail, maybe before the end of the Middle Ages, may have been even more tortuous.

Credit for the photograph appearing on the book's cover: Mario Muchnik

Tuesday, April 21, 2009


Is knowing the genetic mutations that lurk at certain locations of our DNA really useful in terms of assessing our risks with respect to diseases like diabetes or stroke?

Some specialists have lately voiced their doubts about this, countering the idea – which has been dogma these last years – that each common disease is the product of a few common genetic variants. This assumption has motivated dozens of so-called “genome-wide studies”, where geneticists set out to hunt down disease-causing genes through the detection of sets of point mutations – the famous SNPs – that would be frequently present in sick people but not in healthy people.

The problem with this approach is that such a simple situation is actually the exception, says David Goldstein, a geneticist at Duke University, who a few days ago commented on the subject in the New England Journal of Medicine. On the contrary, according to him, the most likely is that in their great majority, common diseases are caused by a myriad of rare mutations that, in a given person combine, as in a genetic lottery, to produce a specific disease.

If that is correct, getting a personal genetic test done by firms such as 23andme – which I did myself – or others is practically useless in terms of finding out our disease risks. The tests those businesses offer are merely a reading of half a million (sometimes a bit more) locations in the DNA molecule near which it has been inferred, from genome-wide studies, that one of those common disease-causing mutations may lie. This means that, in most cases, the results will never let us see the big picture. Better, then, to trust our family history of disease to tell us what to expect – the good, old “clinical history”, so dear to physicians a century ago.

According to Steve Jones, a well-known geneticist at University College London, writing today in the Daily Telegraph, those who order commercial genetic tests are simply throwing their money out the window. Goldstein, for his part, also argues that, if we really want to dig out the true and complex roots of human disease, rather than decoding many little bits of DNA from many people it might be better, from the point of view of medical research, to read the whole DNA sequences – the whole two times three billion letters – of a smaller number of individuals.

But not all the news is bad: up to now, nobody has questioned commercial personal genetic tests from the perspective of genealogy – and by the way, Goldstein is a big experts in that field. In fact, as I see it, that part is much more fun and exciting; I never doubted it and I intend to keep digging.

Wednesday, April 15, 2009


I clearly belong, on my father’s side, to a family of allergic people. Happily for me, I haven’t suffered much from it (I’m allergic to drugs such as penicillin and little else, as far as I’m aware, notwithstanding the occasional itchy skin for reasons unknown). But the men in my family tell a whole different story. I remember, as a child, seeing my father’s hands full of eczema plaques (atopic dermatitis) between his fingers, which he was often scratching. This was due, he explained to us, to the fact that the reagents he used in his lab (he was a biologist), triggered allergic reactions. My brother and his sons have had more serious cases of it all through their lives. The most famous victim of this ailment appears to have been the French painter Paul Gauguin.
This morning, I received confirmation that this disposition for eczema is in fact in our genes. The Spittoon, 23andme’s blog, refers to an article published earlier this month in Nature Genetics which suggests that, although having a clear environmental component, eczema is also genetic. The study concludes that 13 percent of Europeans have a letter T at position 75978964 of their DNA sequence of both their 11th chromosomes (each inherited from one of their parents) – and that this multiplies by 1.46 their odds of getting eczema compared to the general population. I looked up my DNA bases at that precise location and found out I’m… TT. Bingo!
This may not be a very big risk – and maybe that’s why I didn’t get it myself. But another article mentioned in that same Spittoon post mentions that the very same configuration, at the same position in the same chromosome, also raises the risk for contracting Crohn’s disease, an chronic auto-immune inflammation of the bowel. For which I discovered, when I had my genes tested, that my risks are three times higher than average. It seems as though the pieces of the puzzle are starting to click into place.