If the biologic parents both type as D negative and the newborn types as D positive, what is the case?

Donor egg or semen? Have you done molecular testing on the parents for D?

It isn't a donor egg or semen. What are you suspecting in the molecular testing? (I didn't do it).

I'm assuming the weak D testing was negative on the parents. Molecular - just curious if mom and dad happen to be some form of variant D - would be wild if both were. Another more likely thought (and I wouldn't touch this one with a 3,683 thousand foot pole), is paternity certain?

If weak D was not performed, then variant D even in a family may demonstrate different strengths, right?

The whole story is that I got a call from another medical center asking if this case was possible; I immediately said yes fearing, as you said, the reactions if I said anything else. But then I wanted to know if it is at all possible so I put my post. Maybe, they did not perform weak D. (I like to believe he is the father :raincloud they are not in our center). Would Del do anything like this?

You are certain the husband is the father? I have seen this "discrepancy" in the past . . . MD knew married couple were both Rh=, wasn't going to do cord blood workup, but it got sent anyway. Baby Rh+, MD demanded a heel stick Rh: Rh+. He came to get the RhIg and do f/u (ps - the mother was an ob nurse and understood the ramifications of receiving RhIg).

Maybe one of the parents is Rh Null?

Interesting case Dave, are you saying that he was not the father?

How would Rh Null give us a positive offspring?

(and no I am not sure he the father, but in medicine I know that nearly everything is possible and we have exceptions to rules so I am interested in probing to see for my own knowledge if this case is a possibility and what would cause it.. Merci ).

I think you have a number of possibilities, in decreasing order of liklihood

1. Technical error - wrong results, reagents not working properly, not the right person's blood etc.

2. the husband is not the father

3. the 'mother' is not the biological mother

4. the baby has been transfused D+ blood in utero!!!!!!!

5. one of the parents is genetically D+ but is phenotypically Rh null of the regulator type. (This works in the same way as the Oh phenomenon - 2 apparantly group O parents with a group B child - one of the parents is genetically group B but is hh; the other parent has 2 normal H genes which the child inherits allowing him to express the B antigen that the 'Bombay' parent could not express

6. Something else that I can't think of at the moment but no doubt malcolm can...............

As mentioned earlier, 10% of all pregnancies the husband is not the father. It brings back memories of a case in the 80's we had at the hospital. The boyfriend was visiting and the husband arrived and shot him in the heart, fortunately our thoracis surgeon happened to be in the hospital.

Kim

I have a suggestion for the 6th option in the list of Galvania.

If the RhD antigen is weak there is also an other possibility. The strength of the RhD antigen can be weakend if there is an RhC antigen on the other allel.

The same type of weak D (lets take type 1) can give 2+ reactions when the genotype is CDe/cde, while it can be 1+ or less when the fenotype is CDe/Cde.

When you are dealing with an weak D type 2 (which is weaker than the type 1) the reaction is mostly only detectabel in IAT when there is no C on the other allel (cDE/cde), when the genotype is cDE/Cde the reaction will be even weaker. This is seen within a family.

This can be checked easy. Do the RhCcEe fenotyping and you will know more. If the father or the mother has a C antigen and the child not (or only one) this could be possible.

Peter

IME 9/10 the reason is that the father is not the 'father'. This is why antenatal testing has not been dropped for transfusion or haemaglobinopathies.

I have just got back from the IBMS Congres, am out on my feet with tiredness and have got a heavy cold and a chest infection. I have not, therefore, given this much thought (!), but the Regulator type Rhnull sounds good, as does the Ceppelinni effect of the cis RHC gene, but I fear that the real answer may be the "other dad" syndrome!!!!!!!!!!!!!!

I have just got back from the IBMS Congres, am out on my feet with tiredness and have got a heavy cold and a chest infection. I have not, therefore, given this much thought (!), but the Regulator type Rhnull sounds good, as does the Ceppelinni effect of the cis RHC gene, but I fear that the real answer may be the "other dad" syndrome!!!!!!!!!!!!!!

Malcolm, you have such a great work ethic! Now, go lie down and have a hot cuppa with lemon!

Thanks Elizabeth. That is exactly what I am going to do (with just a small touch of whiskey!).

I think you have a number of possibilities, in decreasing order of liklihood

1. Technical error - wrong results, reagents not working properly, not the right person's blood etc.

2. the husband is not the father

3. the 'mother' is not the biological mother

4. the baby has been transfused D+ blood in utero!!!!!!!

5. one of the parents is genetically D+ but is phenotypically Rh null of the regulator type. (This works in the same way as the Oh phenomenon - 2 apparantly group O parents with a group B child - one of the parents is genetically group B but is hh; the other parent has 2 normal H genes which the child inherits allowing him to express the B antigen that the 'Bombay' parent could not express

6. Something else that I can't think of at the moment but no doubt malcolm can...............

All of the options are great to know, thank you.

1 to 5 were not options in this case. # 5 is possible and interesting, as is Peter's reply. So I was not wrong in saying it is possible.

Thank you.

For the replies that this may not be the biologic father, that is what I feared when received the call. But as you know, and as stated in the posts, someone may die. So let them live happily ever after and I really appreciate learning of the other possibilities. Thanks.

Thanks Elizabeth. That is exactly what I am going to do (with just a small touch of whiskey!).

Malcolm, I find that hot lemonade and Jack Daniels is just the thing for a cold.

John, I have always found your posts most instructive - and this is one of your best!!!!!!!!!!

FYI, we have had many instances that mililtary personal in the US are typed as Rh= and they are indeed Rh+. I would take the husband's type with a grain of salt if the same lab is not testing the husband and the child. I personally have issues with believing what type someone is if they were not tested in my lab....

John

Lemonaide (hot or cold) is good for anything and everything!!

When I was entering the Air Force, they asked me what blood type I was. I am not sure if they ever actually typed my blood or just used my answer for my ID card and dog tags. Of course, I had typed my own blood in med tech school so I was confident of my type.

Something similar happened at my workplace...a student rotating through the blood bank asked a coworker if her blood type was possible. She was certain her father was AB+ (he was frequently in the hospital), while she herself was O=. My coworker was stunned but managed to get out that blood types could be complicated and anything was possible.

Something similar happened at my workplace...a student rotating through the blood bank asked a coworker if her blood type was possible. She was certain her father was AB+ (he was frequently in the hospital), while she herself was O=. My coworker was stunned but managed to get out that blood types could be complicated and anything was possible.

Ooooooops!!!!!!!!!

I think your co-worker did the right thing. If she/he had invoked cisAB, it could have got even more complicated, and you can bet your bottom dollar that the internet would have been interrogated - and we all know how accurate that can be!!!!!!!!!!

My husband's Army tags state he is O+ when he is actually B+!!

My husband's Army tags state he is O+ when he is actually B+!!

That's easily fixable with a diamond point and a cleverly placed line