Dickey, 459a & b are paired together. 41020 has 8/8 while everyone else in the green group has 8/9. If something happens to mess up one of these markers it tries to correct itself. It is not unusual for an error to occur in this repair attempt. Sometimes rather than repairing itself it just copies the other marker in the pair. Also these markers have a high mutation rate (the marker names are in RED). I think all of you in the green group share a common ancestor. I believe your 36/37 match with 41020 is a closer match than your 36/37 match with 27450. Here you differ on DYS442, which has a slower mutation rate. The thing we all have to remember is that a mutation at any marker can show up at any birth. I hope this helps. Jim Barrett - Timpson, TX [email protected] wrote: Jim- I hope this makes sense. I (kit#29585) match 36 of 37 markers with kit #41020. Kit#41020 marker 459a is an 8, instead of being a 9, which would be perfect match. This kit is my closest relative on the matches; our 3rd great grandfathers were brothers. Way back when this was first posted you made a comment about the 459a marker(which i have since lost), that there could be a mistake or something. Thanks for all you do. Dickey Powell