The official name of PAX8 gene is “paired box 8". The PAX8 gene belongs to a family of genes that plays a critical role in the formation of tissues and organs during embryonic development. The PAX gene family is also important for maintaining the normal function of certain cells after birth. To carry out these roles, the PAX genes provide instructions for making proteins that attach to specific areas of DNA. By attaching to critical DNA regions, these proteins help control the activity of particular genes (gene expression). On the basis of this action, PAX proteins are called transcription factors.
During embryonic development, the PAX8 protein is thought to activate genes involved in the formation of the kidney and the thyroid gland. The thyroid gland is a butterfly-shaped tissue in the lower neck. It releases hormones that play an important role in regulating growth, brain development, and the rate of chemical reactions in the body (metabolism). Following birth, the PAX8 protein regulates several genes involved in the production of thyroid hormones.
PAX8 proteinLocation:
PAX8 Gene is present in human chromosome 2 and its coded from region113,691,409 to 113,752,967 Complement base pairs with 9 exons, the cytogenetic location 2q12-q14.
Disease
Mutations in PAX8 gene causes congenital hypothyroidism.Several PAX8 mutations have been identified, but the effect of these mutations on health is variable. Some mutations cause congenital hypothyroidism, while others mildly reduce thyroid hormone levels or have no detectable effect. In some cases, identical mutations in members of the same family have varied effects.
Most mutations change one of the building blocks (amino acids) used to make the PAX8 protein. Other mutations disrupt protein production, resulting in an abnormally small version of the PAX8 protein. Nearly all PAX8 mutations prevent the PAX8 protein from effectively binding to DNA. One mutation alters interactions between the PAX8 protein and other transcription factors. As a result, the PAX8 protein cannot perform its role in regulating the activity of certain genes.
The thyroid gland is unusually small in people with PAX8 mutations. This finding suggests that PAX8 mutations disrupt the normal growth or survival of thyroid cells during embryonic development. As a result, the thyroid gland is reduced in size and may be unable to produce the normal amount of thyroid hormones.