Zahra,
With the current method of gene therapy that is slowly progressing into trials, cord blood would probably have no value, as the stem cells have to be stimulated within the patient, so that there are sufficient numbers in which to insert the good genes. I cannot say for certain that some use may or may not be found in the future, as medicine is advancing so rapidly. If the cost of storage is high, a decision to donate them for research would be understandable.