Paternity Blood Typing Test Question

I just received a copy of the disputed paternity blood typing test done when I was a child to prove my “father” was in fact not.

Here are the results:

“Father”: Type A1 M (Rh1 homozygous)
Mom: Type A1 MN (Rh1 homozygous)
Me: Type O MN (Rh1 Rh2 heterozygous)

Conclusion: I have an Rh factor unavailable from my mother, also not present in the “father.”

Could someone translate this for me? A few years back a scientist relative told me the results of the test, at the time (1960’s) excluded the “dad” from paternity but that nowadays these results aren’t conclusive. That true? What are the chances these results aren’t conclusive?

Not that I care so much whether the guy is my father, just want to be sure he isn’t.

I am not a doctor or geneticist, but here’s my understanding based on reading.

You get 2 genes, one from Mom & one from Dad. A person with Type A could genetically be AA or AO. A is dominant over O. So theoretically if both Mom & Dad were genetically AO (heterozygous) they could each have contributed the O gene, resulting in a Type O child. I don’t know what the type M and N are, but if Mom is M and Dad is MN, the child could get the M from Mom and the N from Dad, resulting in type MN.

The interesting part is the Rh notation. Homozygous means possessing only one of type of gene, as opposed to heterozygous, which means having 2 different types. If Mom and Dad are both homozygous for Rh1, then, barring a mutation, they could not have a heterozygous Rh1 Rh2 child. The Rh2 had to come from somebody who was either homozygous R2 or heterozygous R1 R2.

So I think your short analysis is correct – at least one of the two is not your biological parent, unless there was a mutation.

levdrakon - who does blood typing these days? I thought it was all PCR these days.

That’s what jumps out at me. Where did you even find a draw site that does blood testing for DNA?

Speaking as a blood banker I’d like to note that the reagents used nowadays to type blood are much more sensitive than those used thirty-some years ago. I’ve gotten slightly different results on patients than those in their record from many years past. So I guess I’d say, take those results from the '60s with a grain of salt.

dwyr, how big a grain of salt? The test may have yielded inaccurate results or the results as we now understand them don’t exlude his paternity?

If the results listed are correct, they exclude his paternity. The question is the accuracy of those old tests, and I don’t know enough to comment on that.

Thanks Smeghead, guess it comes down to retesting then, if these tests in the '60s were really not that accurate.

Happen to know how much a similar blood test costs these days?

I think you can just phone up Identigene (I think that’s the company name) and get it done for a couple hundred bucks (it’d be DNA testing, though).

Brought to you by Ms. “Home sick as a dog for two days and watched too much Jenny Jones”

Excuse my tardiness.
What Smeghead said. I can’t really comment on the prices though. Not much call for paternity tests at my present job.

I dunno either. A typical sequencing test at our lab, though, which we do for other reasons, runs in the thousands of dollars. I’ve got to think, though, that there are simpler, cheaper, paternity tests out there. Sequencing a whole gene or two seems like overkill to me.

I checked into the DNA test a couple years ago & it was in the range of $600. That’s why I’m willing to go for a simple blood test. They do still do such simple tests don’t they?

You’re right, levdrakon, I checked the site for the company Mynn mentioned (http://www.identigene.com/SWIMX/products/pat_desc_prices.asp) and that’s the price range.

Who will you presenting the results to? I suggesting finding out what’s legally valid for your purposes before spending a dime or spilling a drop of blood.

Of course, if you suspect you have a disease or disorder with genetic markers that are being studied, you can get a free test!

j.c.,
The results are for me. Mom told me he was my father, he has always said he wasn’t. Now I’m older & it all doesn’t make sense. I want to know for sursies.

What diseases, disorders, genetic markers?? I’ll go for a free test!