THE JOHNS HOPKINS HOSPITAL 
BALTIMORE, MARYLAND 21205 
George H. Sack, Jr., M.D., Ph.D. 
Tel. (301) 955-3122 
1 October 1 984 
The Joseph Earle Moore Clinic 
Division of Medical Genetics 
Department of Medicine 
(301) 955-6621 
Dl rector. 
Office of Recombinant DNA Activities 
Bui I ding 31 - Room 3B10 
National Institutes of Health 
Bethesda, Maryland 20205 
Dear Sir: 
I am writing to formally express my concern over the opinions 
of Mr. Jeremy Rlfkln regarding recombinant DNA experiments and 
present In the Federal Register volume 49, number 184, September 
20th, 1984. I understand that the consideration of his proposal 
will be placed on the agenda of your Committee for the October 
29th meeting. 
For both theoretical and practical reasons, the proposed 
gene transfer experiments to which Mr. Rlfkln objects are Important 
and should continue without Interruption. There Is no legitimate 
basis to suppose that laboratory controlled experiments such 
as are planned would represent any difficulty or any threat. 
There are many reasons to suppose that great understanding of 
abnormal physiology would result from gene transfer experiments 
and they have a I ready proved useful In earl l er studies. Proscription 
of such thoughtful and carefully done work only assures that 
It will be done elsewhere under situations where such concern 
and fear are not exercised. Fortunately, the United States 
Is significantly In the forefront of these Important studies 
and maintaining respect and control for this work Is an Important 
function of your Committee. 1 hope that you will consider the 
very serious Implications of any potential limitation of these 
studies. Thank you for your cons' +t 
George H. Sack, Jr. I M. D. ,Ph. D, 
Assoc! ate Prof essor of-MedlcI ne 
of-M< 
Pediatrics, and Biological 
ChemI stry 
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