Pharmacogenomic Response to Thyrotropin-Releasing Hormone Stimulation in Healthy Volunteers:The Influence of a Common Type 2 Deiodinase Genetic Polymorphism on Serum T3
This study intends to examine how a common genetic pattern affects thyroid function. Recent
studies have demonstrated that a substance (enzyme) produced by a gene has an important role
in controlling circulating thyroid hormone levels. A commonly found pattern in this gene
exists in many individuals and might affect the function of the enzyme. These individuals
need higher doses of thyroid hormone medication in certain situations (e.g. in the treatment
of thyroid cancer after the thyroid gland has been removed) than those individuals without
We intend to study this by looking at the response to a hormone-test in healthy volunteers
with different genetic patterns.
We plan to screen healthy volunteers using a blood test to identify their genetic pattern
relating to the enzyme we are interested in. From this group, forty-five healthy volunteers
will be recruited for the hormone-test. This test (called the TRH test) uses a hormone
produced by the brain and stimulates the pituitary and thyroid gland. The response to this
test will allow us to compare the function of the thyroid system in relation to the genetic
pattern of the volunteer.
We hypothesize that the stimulation of the thyroid hormone system will be decreased in
volunteers with a specific genetic pattern and that these individuals will release less
active thyroid hormone from the thyroid gland in response to the TRH test.
This study will provide new information on the effect of a common genetic pattern on thyroid
hormone function and will help us to better understand the way in which the thyroid hormone
system operates. Ultimately, the results of this study might help to provide a more
individualized therapy for patients in need of thyroid hormone replacement.
Time Perspective: Prospective
Francesco S Celi, M.D.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
United States: Federal Government
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