Pharmacogenomic Response to Thyrotropin-Releasing Hormone Stimulation in Healthy Volunteers: The Influence of a Common Type 2 Deiodinase Genetic Polymorphism on Serum T3
Condition: Thyroid Disease; Healthy
MeSH terms: Thyroid Diseases
Study type: Observational

Summary: 
      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
      the variation.

      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.
    

Detailed description: 
      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
      the variation.

      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
Keywords: Type-2 Deiodinase; Genetic Polymorphism; Triiodothyronine (T3); Thyrotropin Releasing Hormone (TRH) Test