Ashkenazi Jews' heritage was traced back to only a few hundred individuals.

Researchers created a data resource in hopes of improving genomic research in the Ashkenazi Jewish population, which could lead to better personalized medicine, Columbia University School of Engineering and Applied Science reported.

Because the population remained so genetically isolated in the past the line has an abundance of population-specific mutations and high prevalence of rare genetic disorders. 

"Our study is the first full DNA sequence dataset available for Ashkenazi Jewish genomes," said Itsik Pe'er, associate professor of computer science at Columbia Engineering. "With this comprehensive catalog of mutations present in the Ashkenazi Jewish population, we will be able to more effectively map disease genes onto the genome and thus gain a better understanding of common disorders. We see this study serving as a vehicle for personalized medicine and a model for researchers working with other populations."

Before the TAGC study data was available only for a very limited number of DNA markers that are common in Europeans. The researchers performed high-depth sequencing of 128 complete genomes of Ashkenazi Jewish healthy individuals to make their findings. They found Ashkenazi Jewish genomes had significantly more mutations that had not yet been mapped. They analyzed the raw data and put together a comprehensive catalogue of the mutations present in the population.

"TAGC advances the goal of bringing personal genomics to the clinic, as it tells the physician whether a mutation in a patient's genome is shared by healthy individuals, and can alleviate concerns that it is causing disease. Without our work, a patient's genome sequence is much harder to interpret, and more prone to create false alarms. We have eliminated two thirds of these false alarms," said Todd Lencz, an investigator at The Feinstein Institute for Medical Research, director of the Laboratory of Analytic Genomics at the Zucker Hillside Hospital, and associate professor of molecular medicine and psychiatry at the Hofstra North Shore-LIJ School of Medicine

The finding also provides insight into the origin of Ashkenazi Jews and Europeans. The data suggests the Ashkenazi Jewish population was founded in the late medieval times by only a few hundred individuals. 

"Our data provides evidence for today's European population being genetically descendant primarily from late mid-eastern migrations that took place after the last ice age, rather than from the first humans to arrive to the continent, more than 40,000 years ago." said Shai Carmi, a post-doctoral scientist who works with Pe'er and who conducted the analysis