A 2013 trans-genome study carried out by 30 geneticists, from 13 universities and academies, from 9 countries, assembling the largest data set available to date, for assessment of Ashkenazi Jewish genetic origins found no evidence of Khazar origin among Ashkenazi Jews. "Thus, analysis of Ashkenazi Jews together with a large sample from the region of the Khazar Khaganate corroborates the earlier results that Ashkenazi Jews derive their ancestry primarily from populations of the Middle East and Europe, that they possess considerable shared ancestry with other Jewish populations, and that there is no indication of a significant genetic contribution either from within or from north of the Caucasus region", the authors concluded.

How many geneticists carried out the 2013 trans-genome study?