I have identified a discrepancy with several test kits that were tested at Ancestry, with results transferred to both Gedmatch and MyHeritage, all relating to the same area at the end of chromosome 19.
For one segment match on chromosome 19, Gedmatch and MyHeritage show the match at two different close but non-overlapping locations:
As you can see, Gedmatch states the match is in the 59M-63M position, while MyHeritage shows this segment in the 54M-59M position. When going to map these results in DNA Painter, they therefore appear to be two distinct segments, when in reality they are actually the same matching segment (the blue and green should be overlapping):
The other segment matches between these two people all are very similar in terms of genomic position, on both Gedmatch and MyHeritage.
Now small differences I could live with, since each service uses different SNPs. But there is something not right here.
How to explain the discrepancy? Is this occuring due an error on the part of Gedmatch, MyHeritage, or with the actual kit data from Ancestry?