Mutations in the SLC16A2 gene cause<unk> . The SLC16A2 gene, also known as MCT8, provides instructions for making a protein that plays a critical role in the development of the nervous system. This protein transports a particular hormone into nerve cells in the developing brain. This hormone, called triiodothyronine or T3, is produced by the thyroid. T3 appears to be critical for the normal formation and growth of nerve cells, as well as the development of junctions between nerve cells (synapses) where cell-to-cell communication occurs. T3 and other forms of thyroid hormone also help regulate the development of other organs and control the rate of chemical reactions in the body. Gene mutations alter the structure and function of the SLC16A2 protein. As a result, this protein is unable to transport T3 into nerve cells effectively. A lack of this critical hormone in certain parts of the brain disrupts normal brain development, resulting in intellectual disability and problems with movement. Excess amounts of T3 circulate in the bloodstream. It is unclear if this is a consequence of compensatory hyperdeiodination or if it results from impaired uptake by certain cell types. Increased T3 levels in the blood may be toxic to some organs and contribute to the signs and symptoms of<unk> . Several studies have documented the potentially dangerous effects of the silymarin mixture on the MCT8 transporter. All of the flavonolignan compounds found in the silymarin mixture seem to block the uptake of thyroid hormones into the cells by selectively blocking the MCT8 transmembrane transporter. The authors of several studies noted that especially silychristin, one of the compounds of the silymarin mixture seems to be perhaps the most powerful and selective inhibitor for the MCT8 transporter. Due to the essential role played by the thyroid hormone in human metabolism in general it is believed that the intake of silymarin can lead to disruptions of the thyroid system. Because the thyroid hormones and the MCT8 as well are known to play a critical role during early and fetal development, the administration of silymarin during pregnancy is especially thought to be dangerous, potentially leading to the<unk> .
Allan–Herndon–Dudley syndrome
Townes–Brocks syndrome
Fryns-Aftimos syndrome
Flynn–Aird syndrome
Kearns–Sayre syndrome
Grisel's syndrome
Dennie–Marfan syndrome
Lujan–Fryns syndrome