<p>I hate to ask this because I’m revealing my ignorance, but here goes.</p>
<p>I have a half-sister L and a half-brother J - we share the same father.<br>
I was from a first marriage, they were from a second marriage.
We did not meet one another til we were all adults, but we have an amiable relationship.
Our mutual father is long deceased.</p>
<p>We tend to connect over genealogical things, as I’m sort of the unofficial historian / keeper of these things.</p>
<p>In any case, L and J each just had testing done through 23andme and L let me know that she was going to give me the password so I could look at their results, thinking that I might find it interesting.</p>
<p>So, here’s my question.
I seem to remember hearing - though I could be wrong - that what the testing reveals favors the mother for women, and the father for men. So L’s results won’t be as useful to me as J’s results (since I don’t have the same mother as L, but I have the same father as J). Am I correct? Should I focus on one over the other?</p>
<p>Would welcome any advice / thoughts!</p>
<p>(I also have a half-sister A, where we have the same mother and different fathers – we were raised together, and she’s my “real sister.”)</p>
<p>Based purely on my own experience, I don’t think that’s true. </p>
<p>My sister and I are half sisters- same dad, different mom (both our dad and my mom did the test as well). Our moms’ backgrounds are very different (hers is northern European and French whereas mine is British and Romani-Hungarian). Some things that we clearly inherited from our dad showed up as very different. For example, my dad was listed as being ~1/3 Ashkenazi Jew but my sister came up as around 1/4 and mine was around 10%. OTOH, even though my mom was over 50% Eastern European, I was listed as just under 20% (in theory, I should be much higher). And even though, in theory, I should be between 25 & 30% British/Irish, mine tested closer to 40%. </p>
<p>If she just had 23andMe done, then it would really only show her ancestral heritage- not genetic conditions (unless she used something like Promethease). I’m not sure how relevant that would be to you unless you know your half-brother/sister’s mom(s) heritage. Since you’re not a male, you can’t trace Y-based DNA and since you don’t have the same mother, you can’t trace mitochondrial DNA. </p>
<p>The DNA test of your half sister will reveal nothing about your genetics as her test will report on her mother’s maternal line, as you say. </p>
<p>Your half brother’s DNA is different. I agree with the other posters that it won’t be your DNA. However it will give your paternal information to the extent that you are sure J is in fact the son of your biological father. It won’t be your DNA, but it will be the same family you’re related to. My brother had FamilyTreeDNA test his DNA, and I accept that those results confirm my genealogy also, since there is no doubt we share the same father. </p>
<p>If there is any doubt at all that your father and his are the same person, then obviously the genealogy is likewise in doubt. </p>
At one time there were a lot of companies like 23and Me, DeCODE, Navigenics, Prometheus (sp?) etc. that were targeting some aspect of the gene sequencing market even at the consumer level, but states began clamping down on many aspects like users ordering medical test without a prescription from a doc, licensing requirements for these companies, not permitting results to be just handed to patients without counseling, and so on, and the FDA followed suit. I haven’t checked recently, but I think you need to use companies based overseas if you want to get health related genetic analysis.</p>
<p>There’s no doubt that we share the same father. (Not that I’m naive about the possibility of these types of things, but this one I can go to the bank on!) </p>
<p>It seems that from my half-brother, I can get the haplogroup? </p>
<p>I did this through National Geographic’s Human Genome project. These tests (for females) track mitochondrial DNA and so follow your mother’s mother’s line. Mine showed no surprises, but remember this is a very limited sample of your DNA. Males get a slightly larger hint.
I wouldn’t use any of these as a medical history. But they’re fun. I’m more Neanderthal than H is, lol.</p>
<p>Each of the three of you got a “random assortment” of exactly 1/2 of your dad’s genes. It is theoretically possible that you share 100% to 0% of that 1/2. But probability is that you should share 50% of that 1/2, or about 25% the same. You and your sister both got the same X chromosome from Dad - neither of you got a Y chromosome. The brother obviously got the Y chromosome. The other 22 chromosomes do not really care if you are male or female. You can inherit non-sex linked (not carried on the x or Y chromosome) genes equally well from the same sex or opposite sex parent.</p>
<p>For everyone, mitochondrial DNA will indicate one’s matrilineal ancestry (i.e. mother, mother’s mother, mother’s mother’s mother, …).</p>
<p>For those with Y chromosomes (i.e. males for nearly all practical purposes*), the Y chromosome will indicate one’s patrilineal ancestry (father, father’s father, father’s father’s father, …).</p>
<p>*There are people with Y chromosomes who have androgen insensitivity or who have a non-functioning SRY (maleness) gene, so they do develop as female rather than male.</p>
<p>I took the 23andMe test; it does not provide any information about genetic conditions. You’ll find out your ancestral heritage, e.g., I was 60% Balkan. Along with the ancestral information, you can get a list of people who have also taken the 23andMe test and are related to you. IIRC you can say if you want your name listed in the print out. You can also fill out a profile and list ancestral names and areas where your family lived. The results will tell you the nature of your relationship to the people listed as relatives, e.g., I have 12 people with whom I share DNA and who are 2nd to 4th cousins. One of those 12 people contacted me and it turns out that we are related on my father’s side. There was also one relative identified on my mother’s side. I contacted her through 23andMe but she never responded. </p>
<p>It seems as though both of them are listed as 95% Ashkenazi, so even though we only share one parent, that kind of gives me a clue here. I can figure out my paternal haplogroup (G2c) so now I’m trying to figure out what that all means. This is a whole new world here of terminology I don’t understand!</p>
<p>Can’t answer your q. PG, but I did want to share that I’ve gotten all sorts of emails through 23andme from supposed 2nd and 3rd cousins, etc wanting to connect and get info. Admittedly it made me a little uncomfortable.</p>
<p>Often when you go live, potential relatives can contact you. I occasionally send out invites if I see anyone new that is in the 2nd-3rd cousin range. </p>
<p>You can put that on private though. It’s not a reason to not do it IMO. </p>
<p>I think it’s worth the $100 to do it if you’re interested in your ancestry at all. </p>
<p>Hah - I’ve sent out loads of e-mails to distant cousins. To be honest I’m even creepier than the folks e-mailing you from 23andme, as I’ve sometimes contacted relatives I’ve tracked down via more old-fashioned methods of research, including some google-stalking as the last step. Fortunately, enough of them haven’t been too weirded out to reply, and I now have a pretty substantial family tree in part as a result of such contacts.</p>
<p>As for your question, PG, I frankly don’t find the mitochondrial DNA results that exciting anyway. I mean,all that it is telling you that your mother’s mother’s mother’s mother’s… mother belonged to a group associated with a certain region. Kind of cool, I guess, but no more relevant than the fact that your father’s mother’s mother’s DNA, or any other of your many ancestral lines, might be traced back to a different group. The mDNA result just happens to be the only one we can trace. Given my Ashkenazi ancestry, I can pretty much assume that I can trace my ancestry back to all or most of the haplogroups typically associated with Ashkenazi Jews.</p>
<p>By the way, I do have an ancestry.com subscription, so if anyone felt comfortable sharing some names (which wouldn’t necessarily involve revealing your own name) and wanted me to do a search for ancestors on there, PM me and I’d be happy to take a look. I love this stuff, and have hit a wall with my own family.</p>
I hope you get the info you were looking for.</p>