Cord Blood Transplant.

I've came across a Thal major patient, after a successful Cord Blood Transplant, a recent test revealed that he is still a Thal minor. The question is, is all Cord Blood packs in the Cord Blood Bank free of Thal gene? Anyone know if the Cord Blood Bank would perform tests to ensure that the Cord Blood Packs are free from thal Gene before the Cord Bloods are released for Transplant?  If no test is done, is there a possibility of getting a Thal Major Cord Blood pack?

Thank you.

It is possible that a genetic disease can be transplanted to patients through cord blood transplants. The chances are small but they do exist.

http://www.bmtinfonet.org/newsletters/issue33/cord.html

One concern voiced about anonymously banking cord blood is that a genetic disorder, not detectable at the time of birth, may subsequently develop in the donor. This information would not be available to the cord blood bank or transplant team. However, the probability of this happening is very low, says Wagner. “Most genetic diseases cannot be transmitted via a bone marrow or cord blood transplant. Moreover, there are several enzyme and DNA tests that can be performed on the cord blood sample that will rule out many genetic diseases.”

http://www.leukemia-lymphoma.org/all_mat_toc.adp?item_id=9622#_q-5

What are the potential disadvantages of cord blood stem cell transplantation?
While cord blood stem cell transplantation is more than a decade old, it is still considered a relatively new procedure in comparison to transplants that use stem cells from peripheral blood or marrow. It is possible that genetic diseases may be present but not apparent at the time of birth and could be transplanted to patients via allogeneic cord blood stem cell transplantation. Follow-up procedures to track this possibility would require follow-up until the infant is months or even years old. Such follow-up has proven difficult, even in countries with free child health care. A partial solution used by many centers is to obtain a detailed questionnaire from potential donors after cord blood collection, similar to standard procedures used to screen volunteer blood donors. The questionnaire covers individual and family histories of disease and ethnic background. If responses to the questionnaire generate medical concern, the cord blood is not collected or discarded or may undergo special testing. A future alternative approach may be genetic testing for diseases that affect the blood and immune system and for certain metabolic diseases that might transplantable.

This may change if recommendations are followed.

http://pediatrics.aappublications.org/cgi/content/full/119/1/165

All cord blood units banked for potential use should be tested for infectious diseases, similar to those tested in a blood bank, and for hereditary hematologic diseases.

The testing that is done on the cord blood may also vary greatly depending on where in the world it takes place and what the regulations are in that country.

There is something that i don't get. What i know is that any transplant (BMT, Cord, blood cells, stem cells) does not change the genotype,  that is to say, genetically, the patient is still having two muted genes  that can inherit to his/her children. Am i correct??

Manal

Yes, Manal.

The Transplant only replaces the existing system of the individual on which the transplant is performed. For example a Thal. Major even though cured with a normal donor will genetically remain Major and transmit his genes to his children.

Thanks Sajid for your reply

Manal

The transplant replaced the bone marrow of my daughter and I believe it's the same for a cord blood transplant. My daughter is still carrying the Thal major gene. A recent eletrophoresis test has indicated that my daughter has "no evidence of Thalassemia". Another patient who undergone a Cord Blood Transplant and I have indicated earlier that, a blood test was carried out to find out if he is still a Thal, and the report indicated that he is still a Thal Minor.

Thank you.

Hi Omega,

The reason that electrophoresis showed "No evidence of Thal." is because this test tests the blood produced by the new marrow (stem cells) which are of the donor and not your daughter's. However if you get her DNA tested from other source than this blood then it will show her own genetic code (or whatever it is called)