I believe I mentioned earlier that I was finally able to contact the
sister of the ancestry.com tester who matches us. I had long speculated he
is descended from John Jr of Casey County. I was correct. But it brought
into question his mismatch at DYS 442. (His test results show 18 repeats
at that location, whereas the rest of us show 12 or 13 repeats.) It turns
out that FTDNA results do not conform (in four instances) to a standard
called NIST. This means that, according to the standard, FTDNA (and other
labs) under-report by *five* repeats at that marker. Making the
adjustment, the tester's results at DYS 442 is 13 repeats.
It seems that many of the big labs do not conform to NIST. Since virtually
all our testing is done at FTDNA, I'm hesitant to adjust the whole page to
NIST standards but to leave them as reported--except for the occasion
exception, such as this one.
See column 10 at
http://ancestraldata.com/ahnentafel/256/ydna.html
-Michael
Received on Tue Sep 11 2012 - 19:50:59 MDT