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vettor
09-23-2014, 06:30 AM
I am wanting to know how important DYS464 is in ancestry matches when it mutates and then gets re-aligned to present a numbered ordered...example.....11-12-14-15 could have a mutation at the last spot to 11-12-14-13 and then gets reset to 11-12-13-14.

my questions are
1 - does this resetting of the number order effect matches.

2 - what does does the first number plays as i was told the first number only changes only after every 24 generations.

3 - since recLOH mutations cause a loss of ancestry information and results in an exact copy of the previous marker for DYD464, why do we bother in using DYS464 for ancestry.

4 - does DYS464 never advance forward but always mutates to a lower number?

5 - does major illness cause a recLOH mutation in DYD464

thanks for help

George Chandler
09-23-2014, 02:49 PM
I am wanting to know how important DYS464 is in ancestry matches when it mutates and then gets re-aligned to present a numbered ordered...example.....11-12-14-15 could have a mutation at the last spot to 11-12-14-13 and then gets reset to 11-12-13-14.

my questions are
1 - does this resetting of the number order effect matches.

2 - what does does the first number plays as i was told the first number only changes only after every 24 generations.

3 - since recLOH mutations cause a loss of ancestry information and results in an exact copy of the previous marker for DYD464, why do we bother in using DYS464 for ancestry.

4 - does DYS464 never advance forward but always mutates to a lower number?

5 - does major illness cause a recLOH mutation in DYD464

thanks for help

Answer #1
Yes it can like with any mutation but it depends on the number of markers which are being compared and the cut off point in terms of a mismatch.

2) Each STR mutation is based on a statistical average. So it's "likely" that the first number will mutate at a certain rate "but" a slow moving marker can mutate and then mutate again within a few generations even though it isn't supposed to mutate on average for another 5,000 years. This is where it's good if you can determine the known historic value through genealogy and testing different lines.

3) A RecLOH doesn't necessarily cause a loss of ancestral information but I guess that could be said about any mutation. It's more difficult to identify a RecLOH event in 464 unless you have a known ancestral group and the RecLOH event is obvious. So lets say you have a 14,15,16,17 for most people in a group with the same surname. Most people have those values and there is very little difference between them say at 111 markers. You then find a person with the same surname who has a 14,14,14,14 or a 14,15, 14,14 etc it's likely a good indication that a RecLOH event has happened. That RecLOH can now be helpful in identifying others from that line.

4) I'm not aware of that? You can get a shift from 19-23 at YCAII to 21-21 so don't see it. The RecLOH just means a "loss of difference" in a location where one can influence the other.

5) I'm not aware of any autosomal causes or illness being a factor.

George

Dr_McNinja
09-23-2014, 05:12 PM
Does DYS464 mutate one value at a time? Can it jump from 13-14-16-16 to 10-14-16-16 in one generation?

vettor
09-23-2014, 06:16 PM
Answer #1
Yes it can like with any mutation but it depends on the number of markers which are being compared and the cut off point in terms of a mismatch.

2) Each STR mutation is based on a statistical average. So it's "likely" that the first number will mutate at a certain rate "but" a slow moving marker can mutate and then mutate again within a few generations even though it isn't supposed to mutate on average for another 5,000 years. This is where it's good if you can determine the known historic value through genealogy and testing different lines.

3) A RecLOH doesn't necessarily cause a loss of ancestral information but I guess that could be said about any mutation. It's more difficult to identify a RecLOH event in 464 unless you have a known ancestral group and the RecLOH event is obvious. So lets say you have a 14,15,16,17 for most people in a group with the same surname. Most people have those values and there is very little difference between them say at 111 markers. You then find a person with the same surname who has a 14,14,14,14 or a 14,15, 14,14 etc it's likely a good indication that a RecLOH event has happened. That RecLOH can now be helpful in identifying others from that line.

4) I'm not aware of that? You can get a shift from 19-23 at YCAII to 21-21 so don't see it. The RecLOH just means a "loss of difference" in a location where one can influence the other.

5) I'm not aware of any autosomal causes or illness being a factor.

George

so, then if in DYS464 and recLOH occurs and with it a resetting of the numbered order , then logically its a useless SNP number to be included in matches.
maybe below, summons it up
http://www.smgf.org/pages/dys464.jspx

I was told that since the first number is always the lowest for DYD464, then this number is an indicator to the age of your entire genetic makeup

George Chandler
09-23-2014, 07:23 PM
Does DYS464 mutate one value at a time? Can it jump from 13-14-16-16 to 10-14-16-16 in one generation?

Yes it can also mutate one value at a time so that's why you have to be careful in determining what is a RecLOH event and what is a one step or series of one step mutations.

George

George Chandler
09-23-2014, 07:28 PM
so, then if in DYS464 and recLOH occurs and with it a resetting of the numbered order , then logically its a useless SNP number to be included in matches.
maybe below, summons it up
http://www.smgf.org/pages/dys464.jspx

I was told that since the first number is always the lowest for DYD464, then this number is an indicator to the age of your entire genetic makeup

Like any mutation it becomes an indicator and a RecLOH is no different. It can be confusing in terms of making it seem like they TMCA is more distant. It's good to look at the pattern of all the markers not just some and consider the possibility at some locations that a RecLOH may be more recent. It's smart be checking SNP data as well if possible.

It's possible for the first value is the oldest but it doesn't have to be so as they can mutate individually or as a RecLOH at anytime.

George

vettor
09-24-2014, 06:34 AM
Like any mutation it becomes an indicator and a RecLOH is no different. It can be confusing in terms of making it seem like they TMCA is more distant. It's good to look at the pattern of all the markers not just some and consider the possibility at some locations that a RecLOH may be more recent. It's smart be checking SNP data as well if possible.

It's possible for the first value is the oldest but it doesn't have to be so as they can mutate individually or as a RecLOH at anytime.

George

thanks

I was reading Tetry Barton in world Families and he has a

We have a man with an 8 step mutation at 557

so it can drop more than 1 step

well, my dys464 are all the same number so who can tell the order anyway

George Chandler
09-24-2014, 02:26 PM
thanks

I was reading Tetry Barton in world Families and he has a

We have a man with an 8 step mutation at 557

so it can drop more than 1 step

well, my dys464 are all the same number so who can tell the order anyway

We have something similar in my group where there is a drop from 12 to 8 at 568 and a drop from 12 to 6 at 589. I'm pretty certain both happened in one event (especially 589). It's really unusual but it can happen.

It's possible you have a RecLOH at 464 for them to all line up but you need to look at your known recent family name cluster to get a better idea. Sometimes you get something like 15,15,14,16 and it goes to 15,15,15,16 in one generation and then 2 generations later you have 15,15,15,15. So although it looks like a RecLOH it really isn't.

The person who did a lot of work on this was Erik Maher who started the 9919 RecLOH project but disappeared about a year ago and we haven't heard from him since. There are some good explanations on the project website if you're interested.

https://www.familytreedna.com/public/RecLOH/default.aspx

George