CONSENT FORM 
Informed Consent 
Lymphocyte Gene Therapy for Mild Hunter Syndrome 
You (or your child) is invited to be in a research study of the 
treatment of mild Hunter syndrome (mucopolysaccharidosis type II). 
You (or your child) were selected as a possible participant 
because you (or your child) have this condition. 
The study is being conducted by the University of Minnesota. We 
request that you read this Consent Form and ask any questions you 
may have before agreeing to be in the study. 
Background Information: 
The overall purpose of this study is to evaluate the possibility 
of treating Hunter syndrome by a form of gene therapy. We hope to 
do this by treating some of your blood cells with a "vector" known 
as "L2SN" . This vector is actually a virus that has been 
genetically modified to carry the normal gene to make the enzyme 
you are lacking (i.e., iduronate-2-sulfatase also referred to as 
"IDS"). The virus has also been modified so that it cannot 
reproduce itself outside of the laboratory and therefore cannot 
cause an infection. 
The vector L2SN will be used to treat some of your blood cells 
called "lymphocytes". The lymphocytes will be removed from your 
body, grown in the laboratory, and exposed to the virus. The 
treated lymphocytes will then be returned to your blood stream by 
intravenous injection. It is hoped that the treated lymphocytes 
will survive in your blood stream for several weeks or longer and 
will be able to partially replenish the IDS enzyme you are 
missing. It is hoped that some of the symptoms of Hunter syndrome 
will be slowed, prevented, or reversed by this treatment. 
The specific goals of this study are to: 
(1) Determine the amounts of IDS enzyme that can be achieved in 
your body after injecting your own lymphocytes which have been 
treated with the virus L2SN. 
(2) Determine how long these genetically modified lymphocytes can 
survive in your blood stream. 
(3) Determine if the genetically modified lymphocytes will reduce 
the abnormal amounts of storage material in your urine. 
(4) Determine if the genetically modified lymphocytes will decrease 
the size of your enlarged liver and spleen, and if this 
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