Genetic testing of banked umbilical cord blood

Autor: Mary E. Clay, D. E. Vawter, Myra J Wick, J. McCullough, Ronald C. McGlennen, T. Eastlund
Rok vydání: 2010
Předmět:
Zdroj: Cytotherapy. 1(4)
ISSN: 1465-3249
Popis: In this letter we focus on the first of these issues and propose an approach to considering testing of cord blood for inherited diseases. Genetic testing should be considered only for diseases involving hematopoietic tissue since other genetic diseases, even if present in the UC blood donor (infant), would not become manifest in the hematopoietic stem-cell recipient. Based on the potential consequences in the hematopoietic stem-cell transplantation setting, we have classified genetic diseases into four categories and present a proposed test (or non-test) strategy for each. This information is summarized in Table 1, along with examples of ‘common’ genetic disorders within each category. The first category includes those diseases which would not be expected to have a clinical effect on the recipient of a hematopoietic cell transplant (e.g. Factor V Leiden, Duchenne muscular dystrophy). Testing for these diseases is not indicated. The second category includes those genetic diseases that are treated by BM transplantation. This involves primarily inherited metabolic diseases. Obviously, if the UC blood donor and recipient are affected with the same metabolic disease, transplantation would be of no benefit. Thus, when transplant is for treatment of these disorders, it is recommended that the UC blood unit intended for transplant be tested for the specific disease. This is currently being done in those few centers that transplant these patients. A secondary benefit of genetic screening of the UC blood unit for a specific metabolic disease is the possibility, although remote, that the blood from an unrelated donor could be shown to have the same genetic disease as the recipient. In this situation, early detection of the disease could possibly lead to early treatment for the donor and avoidance of nervous system damage. General screening of all UC blood samples for metabolic diseases would not be indicated because these disorders are relatively uncommon and testing is costly. The third category comprises those diseases for which transplantation of stem cells containing the defective (or absent) gene could lead to disease manifestation in the transplant recipient. Examples are hemoglobin C, hemoglobin E, sickle cell disease (HbS), glucose-6-phosphate dehydrogenase (GGPD) deficiency and pyruvate kinase (PK) deficiency. Molecular and/or other laboratory testing for each of these diseases is available and economically feasible. All US States have newborn-screening programs for HbS, the results of which are usually sent to the infant’s physician and medical record. Hemoglobin electrophoresis, which is routinely used for the laboratory diagnosis of HbS, also detects other common hemoglobinopathies, b-thalassemia and combinations of the two. Thus, additional testing for the most common diseases in this group can be avoided by reviewing the potential donor’s medical records. In contrast to previously mentioned hemoglobinopathies, definitive testing for a-thalassemia, which is molecular-based, is timeand labor-intensive. Thus, rather than screening for this disorder, testing would be indicated only in specific situations, such as where the ethnic back
Databáze: OpenAIRE
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