Mutations and Age/Health of Father

[geneped]

Mike,
Thanks for the reply. I thought your second paragraph was a good start, but the following paragraphs more or less emphasized the usefulness of GD as a predictor of TMRCA for the general population (My emphasis). That is, the population that is blessed with average or near average mutation rates.

Originally posted by Mike
The key words here are "probability" and "average." Both these words indicate that not every paternal line has the exact same mutation rate, but most have a mutation rate close to the average rate. Some have a much lower mutation rate and others have a much higher rate. But those at the extremes of the range of mutation rates are relatively rare. Think of the shape of a bell curve to illustrate how this works.

I don't disagree with your comments at all, but I see it, the issue alluded to in this thread and, especially by Vinnie

[bob armstrong]

I had a 67 marker Y-DNA test done some weeks ago, plus a 37 marker test for an uncle quite recently, & found I only matched 35/37 with him. I was scoring 14,14, 17, 17, on the 464a-d series, compared to his (more usual for our surname group) 15, 15, 17, 17.
The upshot is that I've now ordered a test for my father to see where he fits in between our results. There may also recLOH to be considered?
From a genealogical point of view, it seems imperative to get several family members to test, as my results didn't fit in quite as closely with some of the members of my surname group as I'd expected, yet my uncle's, 2 steps closer, did.
My solid paper trail goes back to the 1690's, & I'm now getting an extremely distant "cousin" from our pedigree chart tested too.
I'm relatively new to this, & have just ordered a Deep clade SNP to see if my predicted R1b1c haplogroup is accurate.
Forums of this type are particularly useful to "learners" such as myself as they aid the speed of the learning process.
Cheers
Bob

[bob armstrong]

I have now had my uncle,(mentioned in my last message), upgraded to 67 markers, & he matches 65/67 with me. I have had a distant relative, who I have a proven paper trail match to in the 1720's, tested for 37 markers. He matches my father & uncle 36/37, & my scores on 34/37.
The upshot is that due to a recLOH event for me on 464a & b, my distant relative who shares a common ancestor with me in the early 1700's, is one closer to me on the 37-marker test than my father.
I suppose this just demonstrates how useful it is to test other close family members to determine where any unusual mutations took place. My interest in this field is mostly genealogical, & it's been useful for me to see my father & uncle's scores linking our family far more closely to a number of people in our surname group. My personal scores had left me more on the periphery of the mainstream of test results.
Bob

[GhostX]

I have now had my uncle,(mentioned in my last message), upgraded to 67 markers, & he matches 65/67 with me. I have had a distant relative, who I have a proven paper trail match to in the 1720's, tested for 37 markers. He matches my father & uncle 36/37, & my scores on 34/37.
The upshot is that due to a recLOH event for me on 464a & b, my distant relative who shares a common ancestor with me in the early 1700's, is one closer to me on the 37-marker test than my father.
I suppose this just demonstrates how useful it is to test other close family members to determine where any unusual mutations took place. My interest in this field is mostly genealogical, & it's been useful for me to see my father & uncle's scores linking our family far more closely to a number of people in our surname group. My personal scores had left me more on the periphery of the mainstream of test results.
Bob

If I were you, I would consider having the markers that differ between you and your father/uncle retested, as it's very possible that there was a lab error. It would only cost you about $14 to have them retested, from FTDNA's a-la-carte advanced orders menu, and I bet you could have FTDNA refund the price if the results turned out different the second time around.

If this test returns the same results as your previous test, I'd then have your father or uncle's mismatched markers retested.

It's possible that you really do have mutations between you and your father, but it seems highly unlikely that there could have been two separate mutation events in one generation, considering that most markers mutate once every several hundred, or several thousand, generations. A lab error seems far more likely, and they do happen all the time.

[bob armstrong]

Thanks for that, GhostX
I'll probably do that.
Cheers
Bob

[wrboyd]

Mutations In A Paternal Event

I am somewhat new to DNA testing so I hope you will forgive my naivety in this matter.

When I got my first DNA y-STR test results the first questions in my mind were how to compare with others, why were there mutations, and what changes could occur in a single transmission from father to son. To my surprise there seemed to be no good explanation as to why the repeat count could change at a given location or whether many locations could change at once or a single location could change by a large amount. Thus anything relating to MRCA, who or when, was suspect in my mind.

I noticed that any calculations of mutation rate seemed to be for anthropological rather than genealogical reasons. Anthropologically it probably doesn't matter if a single change occurs frequently or a larger change occurs less frequently. It still averages out. OK for anthropology but not usefull for genealogy. There was also some blurring in my mind whether the rates calculated were for STR count changes or SNP mutations which seemed to apply more to anthropology. Again, its not obvious that mutations in the two would have the same root causes.

To the topic of the thread,
I have had two DNA y-STR tests of 43 and 67 markers. Both agree on any common locations. I have found about 20-30 others with very similar haplotypes. Admittedly a small sample but from which I derived a modal haplotype.

My haplotype agrees with the rest except for 3 markers. None of the others have the same value as I at those three markers. My question is how likely is a single event responsible for the 3 changes?

As like the original poster, my father was 54 years old when I was conceived. He had circulation problems diagnosed from a incident a few years earlier when he nearly froze to death. The previous 3 generations were all conceived with the father between 25 and 35.

Unfortunately I am aware of no male relatives to test so I cannot pursue that line.

If finding a reason for mutations in STR counts is problematic I would like to see more anectdotal evidence from families that have had known related members tested. If surname project leaders have access to tests from related individuals it would be great if that information could be pooled and analyzed to better understand the nature of the changes that can occur.

Bob

[darroll]

All of you Y-DNA should match.
1 to 37 was a perfect match.
We had a 66/67 with a fifth cousin.
d