View Full Version : GEDmatch Lazarus Kit?

08-08-2015, 07:24 AM
I want to make a Lazarus Kit on GEDmatch for my father with the following kits:

1) his wife, my mother
2) his 6 children, me and my brothers and sisters
3) his sister, my aunt

I'm just a little confused about how it all works.

I understand how the children contribute: if you subtract the mother from the children, what's left is the father's and each child will contribute some more DNA to the reconstruction. So the first child will reconstruct 50% of the father's DNA since children get half of each parent's DNA, the next child will provide an additional [on average] 25% (since they also had half, but a "half different" half; siblings sharing on average half of their DNA with each other), the next child will provide an additional ~12.5% that is "new" and which doesn't overlap with either of the previous two siblings, the fourth child will add ~6.25%, etc

I'm less certain about how a sibling of the "Lazarus" contributes. Like, I know one thing his sister can/will provide will be the mitochondrial DNA/maternal haplogroup which his own children would not have inherited (since you get that from the mother).

But I'm not sure how else the sibling kit contributes beyond that. How can they be sure that the DNA from the sibling is DNA they shared with the "Lazarus" from their common parents as opposed to DNA they didn't share (since siblings only share ~50%)??

Additionally I'm wondering if it makes sense, in addition to the people mentioned...to include any matches that my aunt has on GEDmatch since these would be cousins of some stripe of my father. Would adding these cousins make the Lazarus kit more accurate...or even possibly less accurate than if they simply weren't included?

I know we're lucky to have 6 kids, male and female, to use along with a sister (who can provide the mitochondrial). I should count my blessings! But I'm just wondering about what the logic of the non-descendent contributions (siblings, cousins, etc) is.