Wednesday, Dr. David B. Goldstein, Wolfson Professor of Genetics at University College, London gave a talk entitled "Historical and medical implications of genetic variation in Jewish populations" in Gerstenzang between 4 p.m. and 5 p.m. Goldstein was introduced by Prof. Lawrence Wangh, (BIOL).The lecture was part of a series of talks being given under population and genetic evolution issues. Goldstein is part of a team at the University College, London that has collected DNA samples from Bantu (African), Yemeni (Arab), and Sephardic Jews and Azhkenazi Jews (including Cohanim -- traditional Jewish priest -- from both communities) to compare the genetic similarity that existed between each of these groups.

Goldstein's lecture dealt with three major points: linkage disequilibrium in medical genetics, when the observed frequency of haplotypes within a population does not agree with the haplotype frequencies predicted by multiplying together the frequency of individual genetic markers in each haplotype, demographic history and linkage, an association in inheritance between traits or attributes and disequilibrium in Jewish populations.

"What can we do to hunt through the genome to find variants that influence the likeliness to get diseases and the reactions of people to drugs or treatments?" Goldstein said at the beginning of his lecture. In recent years, researchers have learned a lot about the patterns of genetic variations. "It is now perfectly feasible to go through the gene list-research capacity has increased what we know about genetic influence on drug reaction," he said.

"How do you go about searching for variants?" Goldstein said. "There are sites that are known to differ from one individual to the next." Goldstein said that researchers generally look at the frequency of mutant forms in a population with a certain condition and then compare them to those of a population without it. "You normally don't find anything," Goldstein said, in regard to this approach.

Researchers pay close attention to each gene because variations can occur. "More often than expected, with linkage disequilibrium, knowing something about a variant gives you information about another," he said.

The cost of this procedure can be dramatically reduced by representing other sites of genetic variation with sites that have already been found, studied and identified within that gene. "There is a lot of enthusiasm for rolling this out to the entire genome -- we can't do that today," Goldstein said. "We can't figure out patterns of association of the entire genome ... it's very costly."

Goldstein discussed the idea that certain human populations are especially conducive to variant tracking. These are founder populations in which the bottleneck effect has caused genetic associations, and old populations in which there are small variants that have greatly affected the population. However, if these human populations do exist, we do not know which ones they are.

Goldstein has studied Jewish mothers and linkage disequilibrium. Researchers have considered how the passing of Jewish identity through maternal descent (since the Jewish population has been in the Diaspora -- the movement from Israel to another country by Jewish people) might have determined the genetic structure of the Jewish population. There have already been various genetic studies within Jewish populations dealing with common genetic origins, mixture with geographical neighbors, and Y-chromosome studies, and the commonality within the Jewish population of a high frequency of the Cohen medical haplotype.

Researchers have compared male and female variation of the Y chromosome and short loops of genetic code passed through maternal descent known as mitochondrial DNA, or mtDNA, between Jewish populations and their non-Jewish host populations. Concerning the Y chromosome, there have not been any significant differences or consistent patterns. However, concerning mtDNA, the Jewish population has lower genetic diversity. In studies, Goldstein and team members have observed that every Jewish population had significantly less diversity than any non-Jewish host population. The frequency of particular mtDNA types among different Jewish populations alludes to the fact that independent events within these populations have changed mtDNA patterns.

While the Y chromosomes in Jewish males share similarities with those of other Middle Eastern males, mtDNA suggests that female founders of Jewish populations in the Diaspora were most likely local rather than Middle Eastern women.

The lecture was presented by Faculty Sponsored Interdisciplinary Seminar on Human and Environmental Sustainability (F.I.S.H.E.S.), the departments of Biology and Near Eastern and Judaic Studies (NEJS) and Strengthening Interdisciplinary Connections.