Geneticists Study Jewish Genes for Disease Clues
Sunday December 16 9:14 PM ET
Geneticists Study Jewish Genes for Disease Clues
By Megan Goldin
http://dailynews.yahoo.com/h/nm/20011216/sc/health_israel_genetics_dc_1.html JERUSALEM (Reuters) - Genetic sleuths in Israel are collecting thousands of blood samples from Jews of European origin in a race to uncover the genetic causes of diseases such as schizophrenia, asthma and Parkinson's disease (news - web sites).
IDgene Pharmaceuticals is so far the only company in Israel with government approval to study the genetic make-up of Ashkenazi Jews in the hope it could help them hone in on the genetic causes of common diseases.
The relatively uniform genes of Ashkenazi Jews are a boon for geneticists who must sift through three billion human DNA sequences and around 40,000 genes in their search for the genetic causes of common and often deadly diseases.
``The population of Ashkenazi Jews is relatively homogenous which facilitates gene discovery,'' said Ariel Darvasi, IDgene's president and a geneticist at Jerusalem's Hebrew University.
Darvasi said the genes that cause diseases are easier to track in a homogenous population because there are less genetic differences in their DNA.
``The homogeneity reduces the genetic noise and the signal comes out more clearly,'' said Darvasi.
His company has collected 10,000 blood samples from Ashkenazi Jews in Israel suffering from eight diseases: asthma, type 2 diabetes, schizophrenia, Parkinson's disease, Alzheimer's disease (news - web sites), breast cancer and colon cancer.
IDgene plans to study the genetic links for some 20 to 30 common diseases prevalent in some one percent of the population.
The genetic profiles of the anonymous Ashkenazi donors in each disease category are being compared to the genetic profiles of a control group of Ashkenazi Jews not suffering from the disease. All the donors have signed consent forms.
By searching for genes that frequently appear among sufferers of a disease, but do not show up among those without the ailment, geneticists can more easily find the genetic needle in the human genome haystack.
ASHKENAZI JEWS
The forefathers of the Ashkenazi community began to settle in parts of Europe during the Roman Empire, particularly after the Romans conquered Jerusalem in AD 70. Ashkenazis now make up more than 80 percent of world Jewry.
They moved to Spain, France, Italy and other Mediterranean basin countries, but spread over the centuries to the Rhineland in Germany, Poland and Russia. Frequent persecution kept their numbers small.
Modern Ashkenazi Jews are believed to descend from about 1,500 Jewish families dating back to the 14th century. But Darvasi said the forefathers of today's Ashkenazis came from an even smaller gene pool.
Darvasi said ``maybe 500 families were really the source of the total (Ashkenazi) population today...probably in the order of 100 independent chromosomes,'' because they enjoyed better nutrition and had lower infant mortality rates than less affluent Jews.
In the 18th century, Ashkenazi Jews began to flourish and their numbers swelled to around 10 million today.
For religious and historical reasons, most Ashkenazi Jews married within their community, a phenomena that Darvasi said shows up in the Ashkenazi genes he studies which tend to have a high degree of similarity.
HOMOGENOUS GENE POOLS
Darvasi said the 2.8 million Ashkenazi Jews in Israel provide a very large homogenous gene pool for researchers.
But there are non-Jewish groups, including Sardinians and French Canadians, who have similar potential in that they too are a relatively large pool of homogenous people to study, he said.
Iceland's deCODE genetics Inc has a head start over IDgene which began work two years ago.
DeCODE has already reported finding 350 genes linked to more than 40 common diseases.
Reykjavik-based deCODE is sorting through the medical records of Iceland's population of around 300,000 people which it says has changed little in genetic make-up since the Vikings arrived in the ninth and 10th centuries.
But Darvasi said geneticists disagree over the degree of homogeneity of Iceland's population, which according to some studies also includes people of Norwegian and Celtic descent.
In January, IDgene announced a $7.65 million second investment round by venture capitalists Apax Partners and IsraelSeed Partners and the British-based Wellcome Trust, one of the world's leading financiers of genetic research.
Darvasi said it will take researchers years to isolate the genes responsible for various diseases. But once they do, it will be possible to start developing drugs designed to treat the specific biological causes of the disease.
``Each gene encodes a protein...Once you identify it you can look at the chemical pathway it invokes,'' he said. ``We try through genetics to understand the biology of the disease and treat the disease with that knowledge.''
He said he is not concerned about the competition from Iceland and other companies studying other homogenous genetic groups.
``Most of this field is unknown so chances are that each of us will get something out of our research,'' Darvasi said.
"The forefathers of the Ashkenazi community began to settle in parts of Europe during the Roman Empire, particularly after the Romans conquered Jerusalem in AD 70. Ashkenazis now make up more than 80 percent of world Jewry."
Actually, Jerusalem was conquered by the Romans well before 70 AD. Jerusalem was besieged and actually destroyed in the year 70 AD by the Romans Legions under Titus. I will not pretend to be an expert on the Ashkenazi or Sephardic population statistics. In fact I am not an expert on anything. I have read some, and it seems to me that the nbrs that you quote concerning the World Jewry are likely to be spurious indeed.
In the end it matters not. God knows all things.
The Jews were Hellenized well before the fall of Jerusalem. There are some who have actually argued with distinction that it was only the rise of the Christian cult that caused the "Jews" to be saved from assimilation by the World. Israel would have fallen forever, but the Diasapora is what saved the Jewish Culture forever. If there were no Diasapora, there would never have been a birth of the Talmud. Arguably, the Talmud saved the Jewish culture for posterity, and likely forever.
In the end, it seems to me, that indeed everything happens for a reason.