specially designed to make the IDS enzyme. It is possible that 
this virus could be contaminated by other viruses or microbes 
during the manufacturing process. These unwanted viruses and 
microbes could cause serious infections. Precautions are taken 
to prevent such contamination and to test for contamination. 
However, even the best precautions and tests are not perfect 
and you will be monitored for signs of infection. 
(4) The amount of radiation you will receive from the X-ray tests 
done during this 1-year study are estimated to have the same 
effect as one would get from naturally occurring radiation 
sources (i.e., the sun, the earth, brick walls, etc.) in a 
period of about two-and-a-half years. You may not be eligible 
for this research study if you have participated in any other 
study within the past 12 months. It is your responsibility to 
inform Dr. Whitley of such involvement prior to entering into 
this study. 
(5) An unlikely, theoretical risk of gene therapy is the risk of 
cancer. The groups who regulate clinical trials of gene 
therapy (such as this clinical trial) have felt that the risk 
of developing such cancers is low. No such new cancers have 
occurred in the more than 28 patients who have been treated in 
similar clinical trials of lymphocyte gene transfer. 
(6) Our current knowledge of this form of gene therapy indicates 
that treatment of your lymphocytes with the virus does not 
correct the reproductive cells (i.e., sperm or eggs). 
Therefore, lymphocyte gene therapy does not change the fact 
that males who have Hunter syndrome can transmit the mutant 
gene for this condition to their daughters who will become 
“carriers" of the gene for Hunter syndrome. 
The benefits of participation are: 
(1) If these treatments are successful, symptoms of Hunter syndrome 
may be reduced which could help sustain normal heart and 
breathing functions, reduce the size of your liver and spleen, 
and increase your life-span. There might also be other 
improvements such as increased joint mobility. While this 
research is designed to measure the effects of treatment, it is 
not known if improvements will actually occur. Also, it is not 
known how many treatments will be required to achieve such 
improvements. Of note, it is likely that any improvements 
resulting from this treatment will stop as soon as the 
treatment is discontinued. 
Compensation: 
You will receive no payment for participation in the study. 
In the event that this research activity results in an injury, 
treatment will be available, including first aid, emergency 
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