We have a situation which in classical genetics tests, with the tiny test tubes and microplates, would scream cross-contamination.
cast: son, mother, mother's cousin, step-father, and off-stage (dead) the biological father.
setting: geographically quite distinct locations for the 3 known families.
-The son and cousin were tested some time ago. This cousin is by far the mother's closest match after her son and his child.
-The mother and step-father apparently did their swabbing at the same time, though nobody was there to observe how they did it. . They say he did his own swabbing, and helped her do hers, then they mailed the kits simultaneously. The kits arrived at FT about a week apart. The results were released about 10 days apart - the step-father's first. If there was any cross-contamination it was at home, not in the lab.
-Searching the step-father's matches for his surname popped up only one match, his step-son. Okay - 1st hypothesis, the step-father is somehow distantly related to either his wife or the biological father of his step-son.
-The match was confirmed using the gedmatch one to one tool. Looking at the one significant shared segment only about 4-5 kits shared it: a couple of ancestry strangers, the stepson, and two tests done on the mother's cousin. Hypothesis narrowed down: step-father is related to the mother, his wife.
-Then the results for the mother arrived - surprise. Total confusion.
1. The mother matches her son and her cousin. She does not match her husband (the stepfather).
2. The Stepfather matches her son, and shares a segment with both the son and the wife's cousin, a segment she doesn't share (!!!) This segment is quite clear on both the FT and gedmatch chromosome views, it's about 10.7 cM
3. Matches in common?
mother-son: FT 993 (of 3127) gedmatch >100 (quit counting)
mother-stepfather (her husband): FT NA gedmatch 14 (at default 10/10 level)
mother-her cousin: FT 37 gedmatch 37
stepfather-son FT 0 gedmatch 17 (not including the mother)
stepfather-wife's cousin FT NA gedmatch 1 (the son)
son-mother's cousin FT 29 (of 2607) gedmatch 32
??? Any ideas? I would think the link is through the mother, but she absolutely does not show that shared segment. And it the link is through the biological father, how do we explain the cousin?
cast: son, mother, mother's cousin, step-father, and off-stage (dead) the biological father.
setting: geographically quite distinct locations for the 3 known families.
-The son and cousin were tested some time ago. This cousin is by far the mother's closest match after her son and his child.
-The mother and step-father apparently did their swabbing at the same time, though nobody was there to observe how they did it. . They say he did his own swabbing, and helped her do hers, then they mailed the kits simultaneously. The kits arrived at FT about a week apart. The results were released about 10 days apart - the step-father's first. If there was any cross-contamination it was at home, not in the lab.
-Searching the step-father's matches for his surname popped up only one match, his step-son. Okay - 1st hypothesis, the step-father is somehow distantly related to either his wife or the biological father of his step-son.
-The match was confirmed using the gedmatch one to one tool. Looking at the one significant shared segment only about 4-5 kits shared it: a couple of ancestry strangers, the stepson, and two tests done on the mother's cousin. Hypothesis narrowed down: step-father is related to the mother, his wife.
-Then the results for the mother arrived - surprise. Total confusion.
1. The mother matches her son and her cousin. She does not match her husband (the stepfather).
2. The Stepfather matches her son, and shares a segment with both the son and the wife's cousin, a segment she doesn't share (!!!) This segment is quite clear on both the FT and gedmatch chromosome views, it's about 10.7 cM
3. Matches in common?
mother-son: FT 993 (of 3127) gedmatch >100 (quit counting)
mother-stepfather (her husband): FT NA gedmatch 14 (at default 10/10 level)
mother-her cousin: FT 37 gedmatch 37
stepfather-son FT 0 gedmatch 17 (not including the mother)
stepfather-wife's cousin FT NA gedmatch 1 (the son)
son-mother's cousin FT 29 (of 2607) gedmatch 32
??? Any ideas? I would think the link is through the mother, but she absolutely does not show that shared segment. And it the link is through the biological father, how do we explain the cousin?
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