Interesting problem here–I’m the world’s expert on a fairly big literary figure, and at a recent conference, a young woman attended, and presented her “claim” (more like a polite query) that she might be the granddaughter of a still-living illegitimate son of this literary figure. (Well, she IS his granddaughter–he MIGHT be an illegitimate child.) The grandfather/possible illegitimate child doesn’t have of a clue as to his questionable paternity.
The granddaughter came to ask if anyone could help her out. I did, in two ways: 1) I pointed to certain semi-autobiographical texts that might contain clues as to her great-grandmother’s affair with this literary figure, and 2) I mentioned that I will be meeting soon with the only known child of this literary figure, and if she liked I could broach the subject of having a half-brother.
I met with this (now 65-year-old) legitimate child yesterday, and found out that she was not offended by the idea at all, but rather interested. Assuming this is going to be exciting for the young woman posing the question, I’m wondering how DNA testing works: would it be ethical to obtain a sample from the possibly-illegitimate son without his knowledge, have it tested against the legitimate daughter’s DNA, and find out if it’s a match before raising the subject with him? Does the gender of the two DNA-contributors matter? Would I be better off getting a sample from the legitimate daughter’s SON, rather her herself, to match up male to male? How expensive is this? (I’m not planning on paying for anything, since I’m a mere facilitator–the legitimate daughter is averse to publiciity, and speaks about her father to a few people , me among them. I imagine the DNA testing will be paid for by the young woman, but I’d like to help her find a lab that does this, and to have some idea how much the testing will cost.) I don’t need answers right this minute, but both people in question are rather elderly, so I do need a clue fairly soon. So --can I arrange for a DNA test? How do I arrange it–who does this work? How much does it cost? To what extent is permission from the DNA sources necessary? Any and all information will be helpful.
Are you sure that the potentially illegitimate son has no suspicion? Depending on how close he was to his mother I would think that it would certainly be possible that he could pick up some hints.
Are you asking about the legalities or ethics of testing someone’s DNA behind their back? I remember one of the police shows in the US had the cops swiping trash discarded by a suspect so they could run DNA tests, so it might be ok. You might run into medical privacy issues, though. I don’t even know what type of attorney to talk to on this.
Pretty sure of the first–that’s what the granddaughter says–that his mother (her great-grandmother blabbed to other family members about her involvement with the famous literary figure, but never to him. So she got the rumor corroberated several times over, but he doesn’t seem to have clue one.
On the second question, I’m primarily posing a “how-to” question: assuming I get the ethics and agreements in order, to whom would I go to get the DNA testing done, and whom would I need samples from? Any insights into the reasoning for needing a sample from a particular person (m/F, the sibling or a descendant, etc) would be appreciated.
Some DNA labs will do tests for aunt/uncle and other relationships. They routinely advertise grandparent matches and such.
We have 46 chromosomes; a child gets half, randomly, 26, so 2 half-siblings will have about 13 in common. A child will get about half, may have about 6 chromosomes in common with a half-aunt. The 1-in10-billion match tests should detect that level of common genetics (assuming there is no other path for common genes). However, the closer the relationship the easier for the lab to determine it. (IIRC, most labs do a 16-point allele match, which means if I understand it they are not necessarily checking every chromosome. )
If you can sneak a sample and it does not bother you, sibling tests are best. Otherwise, a perfectly legit test would be the two consenting adults, daughter and half-aunt. Who knows whether he has a clue or not? Somewhere around age 16 to age 46 most people come to the realization their parents have had sex at least once or twice.
Male line is only useful if it is direct. Son of a son of a son… there is only 1 Y chromosome, which determines male (women have 2 X’s). A daughter has the X from her father (and one of her mother’s), a son definitely has the Y and no X from the father - so his daughter has 2 X’s, one from the mother and one from his mother.
Google DNA tests online. Many labs will do mail-order work, and while paternity is the usual test, often advertise the less direct relationship tests too. IIRC it costs a few hundred - they mail you cheek swabs if you need to take a direct sample. Some will work with other samples, if blood on a used band-aid or such is all you can come up with.
On the first question, someone’s DNA sample might be considered private under HIPAA, which could mean that the testing place could not release results from tests run on the grandfather’s DNA without his authorization. Many states also have their own privacy laws that might apply.
Are both women only children? The woman’s son won’t have the Y-DNA of her father, but her husband’s. The best way to do this would be to get a direct son (or son of a son) on famous line since you have a son on the unknown line. The Y-DNA test will be able to tell you for certain if the two share a same male line, but you can’t test women for Y-DNA as they are XX.
It’s best if you can get a DNA sample from the possible son, but the woman will do in a pinch. You can use a service like Family Tree DNA to prepare the samples. The ‘Family Finder’ test is what you need on FamilyTreeDNA. My family has been doing these kits and they either involve a cheek swipe or saliva. Once you upload both profiles, they will tell you how likely they are to be kin and the estimated distance of kinship. It isn’t foolproof, which is why getting the Y-DNA line is best.
The two oldsters are putative half-siblings so their genetic closeness would be the same as uncle-niece. If you substitute a child for one of these oldsters, closeness would be the same as 1st cousin, which may be the most distant relationship available in “off-the-shelf” testing. (One site quotes £375 for uncle-niece, £495 for 1st cousin, and disallows half-cousin tests. I don’t understand the price difference since both tests are “up to 46 markers.” Maybe they check a subset first, remaining markers if they need to, and are more likely to need to for the cousin test.)
As md2000 mentioned, the testees’ sex won’t matter unless you can find a purely patrilineal descendant of the literary figure.
Nitpick: during meiosis chromosome pairs may crossover (typically 2 to 4 times per pair). A child will have about 1/8 of its alleles in common with a half-aunt, but those are better described as “46 eighth-chromosomes”, rather than “about 6 chromosomes.”