Amniocentesis results

Hello everyone. I've been reading the posting last few days on this website and it is just amazing and motivating to see the energy here to help out each other. Thanks so much. I'm hoping to share my experience and also find some more answers.

My wife and I got blood test done from a lab here in California to identify the mutations for thal minor:

  wife: HBB:c.92+1G>T (also known as IVS-I-1(G->T) )
  me  : 619 bp deletion

She got her amniocentesis done in the 16th week of pregnancy and the samples were sent to the same lab. The samples were collected in two flasks. The lab reported the final results on the first flask during the 22nd week:

  Maternal Cell Contamination Study
  Fetus has wife mutation, but not husbands.

Now my wife is in her 25th week, and they haven't reported results on the second flask. The genetic counselor doesn't expect anything different which is great. But we are still tensed because she is in her 25th week.

My questions:
 1) How accurate are such results from Amniocentesis ? Specially for deletions ? Is 619 bp deletion easy to detect, if present ?
 2) Any reason why it is taking such a long time for results to arrive ? Anything else I need to worry about?

Thanks a lot to everyone.
Sumit

The amnio test is normally over 99% accurate, but results can be affected as the pregnancy proceeds. The later the test is done, the higher the chances of maternal contamination affecting the results. She did have it done fairly early, so this is less likely, which means the test has more likelihood of being accurate. Has the lab been contacted as to why the second test results have not yet been reported? It may just be an omission by the lab, or a judgment that since the first test showed only one thal gene, that it may not be necessary. For your own peace of mind, you should get an answer to this. Have your doctor contact the lab and find out if these results will also be given. Your deletion is one that is routinely found in testing, so it's unlikely it would be missed. Unless your report said something specific about the level of maternal contamination affecting the test, you should have nothing to worry about.

You both carry beta zero thal deletions. If a child was to inherit both, the child would be a thal major. Genetic counseling is recommended before attempting any future pregnancies.

Thanks Andy.

We got the second report today and it confirms the first report. The baby has my wifes mutation and not mine. I'm not sure why it took so long for the second test to come back, maybe they were doing a more through investigation ? In  a way, it is good that the test was repeated twice, right?

Also, I got these tests done from Quest Diagnostics (Nichols institute) in California. My genetic conseller told me that Quest is one of the premiur institutes for these kind of tests. Anyone else has any feedback or heard of Quest ?

Thanks again.

Sumit,

That is great news!  I wish your wife a healthy pregnancy and your baby a healthy arrival:)

Best,

Sharmin

Quest is a major chain of labs that is well known. You should have full confidence in their findings. You should put your minds at ease and concentrate on a healthy delivery and bonding with your baby when it is born. Please don't let this distract you any further from your gift.

Consider yourselves fortunate. If both parents' thal genes were present, your child would have a severe, transfusion dependent thalassemia, and would most likely require transfusions during its first 6 months. As I mentioned, genetic counseling is a must for any future children.

Thanks Andy and Sharmin!

I've one more question if anyone has time to shed some light. I was reading the following post where the mother is Thal Minor and father is HBD:
  http://www.thalassemiapatientsandfriends.com/index.php/topic,3998.0/highlight,cvs.html

As Andy noted in the post below that both me and my wife are beta zero thal minors. Amniocentesis results indicate that baby has my wife's mutation but not my mutation. Is it possible that the baby got any HBD mutation from me ? I don't even know if I carry any HBD trait. I'm 32 years old and have never received any transfusions. Doctors diagnosed me with Thal minor from my blood work.

Thanks a lot.

Regarding my question in my previous post - I found my related blood work. The normal ranges on the report are within brackets below

  Hgb A  - 94.7  (94.0 - 98.0)
  Hgb S  - 0.0
  Hgb C  - 0.0
  Hgb A2 - 5.3  (0.7 - 3.1)
  Hgb F  - 0.0
  Hgb Variant - 0.0

  MCV  61     (80 - 98)
  MCH 19.6   (27 - 34)
  MCHC 31.9 (32 - 36)
  RDW  17.5 (11.7 - 15)
  RBC  7.04  (4.1 - 5.6)
  Hemaglobin 13.8  (12.5 - 17)
  Hematocrit 43.2  (36 - 50)

  Interpretation: Hemoglobin pattern and concentrations are consistent with beta-thalassemia minor.

If you had hemoglobin D it would appear in the electrophoresis report. It does not. Your baby's reports have been very specific and you have the advantage of knowing exactly which beta deletions to look for in the DNA analysis. There is no reason to expect anything other than a child that carries your healthy beta globin gene and your wife's thal gene.

Your Hb is quite good for a beta zero minor. I am curious if your alpha globin genes were also examined in the DNA analysis. I don't want to jump to conclusions, but I mention this only because a deletion in an alpha gene somewhat cancels out the effect of the beta thal deletion in some thal minors, leading to a normal Hb in spite of being a beta zero minor. Sharmin's husband falls into this group. This is absolutely nothing to concern yourself about, because it is actually a positive to have an alpha deletion if you have a beta mutation or deletion because it leads to a better balance of alpha and beta globin, eliminating much or all of the negatives caused by this globin imbalance in thal minor. Have you ever had any symptoms of anemia anytime in your life or have you been pretty much normal in terms of energy level and endurance?

Andy, thanks for such a prompt reply.

No, I don't think they examined my alpha globin genes. From your comment, if I were to have a alpha gene mutation/deletion and if that passes on to the baby, it is not really a problem ? Baby already has my wife's beta thal gene. Please confirm.

Regarding my energy levels - I'm mostly active but I do have some symptoms of tiredness. I get out of breadth lot quickly. I've specially noticed that once I turned 28-30 year old. I also have very low vitamin D level (13).

No, it would not pose any problem for the baby. It would actually create an advantage if an alpha gene was also deleted.

Hello all,

My son is 7 months now. Should I get his Hemaglobin checked and electrophoresis ?  His prenatal testing showed that he is Thal Minor, as detailed in this posting.

The pediatrician said that she usually does the testing for anemia at 9 months because infants see a drop in their Hemaglobin between 6-9 months.

My son is active, about 18 pounds in weight. He did get viral infection when he was 3 months and 7 months. The one at 7 months was when he started going to daycare - he had pretty high fever for 3-4 days. They did a CBC on him then and his numbers are:
 
  Hgb - 9.2  (the doctor said the normal is 9.4-13 for infants of this age)
  Hct  - 28.4
  MCV - 56.8
  MCH - 18.4
  MCHC - 32.4
  RDW  - 21.2

Thanks,
Sumit

I would suggest waiting, as the doctor has recommended. In the 10th month, you are more likely to get accurate test results. Make sure he has good dietary sources of iron and not just iron fortified foods. I do not know if it's because of his age, but the MCV and MCH are low and the RDW is high, all in a range where iron deficiency may also be present in addition to thal minor.

Thanks Andy. Would you think his Hemoglobin is on the low side ? Anything to worry about ? Or is this expected for thal minor infants ?

The thal minor status was confirmed during amniocentesis.

I've some more questions - his current viral infection (at 7 months) has caused fever to last longer than what the doc expects (6 days now instead of 2-3 days). but he is eating/playing better than when it started and the fever is less frequent (every 8 hrs instead of every 5 hrs). The fever is between 101-102.

The blood and urine work didn't show any bacterial infection. So, they are expecting it to be viral but the fever has lasted longer than they think it should.

Anyway his blood counts would be doing some of this ?

Thanks again,
Sumit