Dear Customers,

Ethnoancestry has recalibrated the markers in the YSTR18 product. Until 
now, all markers were calibrated to Kayser et al. (2004) Am J Hum 
Genet 74: 1183-1197, but the actual number of repeats was unknown for 
two loci (as in Kayser et al). For these two markers, instead of 
actual repeat counts, the shortest observed allele was called 1, and 
increases of one or more repeat unit(s) were represented by increasing 
this number by 1 or more such that alleles were still comparable 
across individuals. These two markers and the others have now been 
recalibrated to the repeat counts in Lim et al. (2007) Int J Legal Med 
121:124-127 – attached. In both cases calibration was performed using 
some of the same standard DNA(s) used in these two papers and kindly 
provided by the authors. The standardisation to these counts will 
allow comparability with future forensic and academic publications.

For the following nine markers there is no change in the repeat 
nomenclature, so the allele scores remain the same:

DYS575
DYS638
DYS487
DYS549
DYS641
DYS533
DYS556
DYS505
DYS578

For the following nine markers the nomenclature is changing, to 
convert from the old naming system to the new standardisation, add to 
or subtract from the repeat count as shown in the conversion column:

marker  conversion
DYS522  subtract 1
DYS589  add 10
DYS594  subtract 1
DYF406S1  add 7
DYS494  subtract 1
DYS636  add 1
DYS481  add 3
DYS490  add 1
DYS531  subtract 1


The two markers for which we did not have repeat counts are now 
standardised and in most other cases the differences are the result of 
a difference between the naming system of Kayser et al and Lim et al.

Customers will each receive their recalibrated allele scores in a pdf 
by the end of this week.

With regard to the differences in allele nomenclature with FTDNA, we 
would note that in spite of correspondence in June and again in 
October last year we were still waiting for a satisfactory reply. 
There are two markers for which the FTDNA nomenclature differs from 
the standard:

DYS594  subtract 1
DYS481  subtract 1

It would be hoped that FTDNA would calibrate to the same standards. I 
am sorry for the inconvenience this will cause to researchers and 
others in the genetic genealogy community if they do not, but it is 
important to me that our counts are standardised with the academic 
sphere.

With best wishes,

Jim Wilson,
Director
EthnoAncestry