Why doesn't Wilson's Syndrome show up on thyroid tests

Thyroid production of T4: what can be tested

The thyroid system regulates many cell functions, including your body's temperature. Temperature is fundamentally important because the chemical reactions in all of your body's cells have an optimum temperature at which they work best. That temperature range is the same for all cells. Temperatures too high or too low mean your body's fundamental chemical processes are out of whack. The symptoms of Wilson's Syndrome shows how a moderately low temperature resulting from hypothyroidism (too little regulating hormone) can affect widely different systems in the body.

The thyroid system is, in fact, a system, and is composed of more than just the thyroid gland. Proper production of T3, the key hormone for cell activity, goes through a number of steps in the body before ending up successfully working in each cell.

The steps begin with the hypothalamus gland and the pituitary gland, which together affect the thyroid gland's production of a hormone called T4. Physicians commonly refer to these three glands as the HPA axis. If the body has too much or too little T4, there is a problem in the HPA axis (either in the hypothalamus, the pituitary, or the thyroid). In the vast majority of individuals with underproduction of T4, it is the thyroid that is not functioning properly. Medical science today has become very sophisticated at detecting problems in any one of the three glands. The most well regarded and understood blood tests for thyroid conditions detect problems in the HPA axis. The most widely known, used and regarded of these tests is the TSH test. When its is significantly out of range there is clearly something amiss in the HPA axis.

Peripheral conversion: what doesn't show up

But the functioning of the thyroid system doesn't stop with the production of T4 by the thyroid. There are two more critical steps. If there is a problem in either, the cells will not get the T3 the way they need it.

First, the T4 must be converted into T3, the key hormone. Conversion of T3 takes place throughout the body, but mostly in the liver and the kidneys. If there is a problem in this peripheral conversion the cells will not receive the T3 they need. Finally, once the T3 enters each cell it must plug into the proper receptors in the cell. One might think of putting a key into a car in order to start the engine. If there is a problem with the T3 receptor connection, again the cells will not get the proper T3 activation.

Biological knowledge of peripheral conversion and T3 cell activation is in its infancy compared to the medical knowledge of problems in the HPA axis. The tests that are available to monitor these stages of the thyroid system are likewise in their infancy. Nothing, for example, measures whether the individual cells are functioning with the optimum T3 required.

It is clear that Wilson's Low Thyroid Syndrome is caused by a problem somewhere in these last two steps beyond the thyroid gland -- beyond where it would be detected by the sophisticated HPA tests. Some research exists showing that problems can occur these last steps, but information about the biochemical process and the conditions that trigger them continues to be sparse.