Reviewed May 2006
What is the official name of the TSHB gene?
The official name of this gene is “thyroid stimulating hormone, beta.”
TSHB is the gene's official symbol. The TSHB gene is also known by other names, listed below.
What is the normal function of the TSHB gene?
The TSHB gene provides instructions for making a protein subunit of a hormone called thyroid stimulating hormone (TSH). Thyroid stimulating hormone consists of two subunits called alpha and beta. The TSHB gene provides instructions for making the beta (B) subunit of thyroid stimulating hormone. The alpha and beta subunits are bound together to produce the active form of the hormone. A particular segment of the beta subunit, known as the buckle or seatbelt, wraps around the alpha subunit to form the functional hormone.
Thyroid stimulating hormone is made in the pituitary gland, a gland at the base of the brain. This hormone plays an important role in the growth and function of the thyroid gland, a butterfly-shaped tissue in the lower neck. It also stimulates the production of thyroid hormones, which play a critical role in regulating growth, brain development, and the rate of chemical reactions in the body (metabolism). The pituitary gland monitors levels of thyroid hormones. When thyroid hormone levels are too low, the pituitary gland releases thyroid stimulating hormone into the bloodstream. Thyroid stimulating hormone, in turn, signals increased thyroid gland growth and production of thyroid hormones.
How are changes in the TSHB gene related to health conditions?
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congenital hypothyroidism - caused by mutations in the TSHB gene
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Researchers have identified several TSHB mutations that alter the size or shape of the thyroid stimulating hormone beta subunit. Many of these mutations affect the beta subunit's seatbelt region, which holds the alpha subunit in place and stabilizes the hormone's structure. Some mutations severely shorten the beta subunit, eliminating the seatbelt region partially or entirely. Other mutations change the chemical building blocks (amino acids) used to make the beta subunit. As a result, the seatbelt region cannot buckle around the alpha subunit. TSHB mutations prevent the production of functional thyroid stimulating hormone or its release (secretion) from the pituitary gland. As a result, thyroid hormone production is not stimulated, leading to low hormone levels that are characteristic of congenital hypothyroidism. Additionally, the thyroid gland is reduced in size (hypoplastic) because its growth is not stimulated.
Where is the TSHB gene located?
Cytogenetic Location: 1p13
Molecular Location on chromosome 1: base pairs 115,373,937 to 115,378,463
The TSHB gene is located on the short (p) arm of chromosome 1 at position 13.
More precisely, the TSHB gene is located from base pair 115,373,937 to base pair 115,378,463 on chromosome 1.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about TSHB?
You may also be interested in these resources, which are designed for genetics professionals and researchers.
- PubMed - Recent literature
- OMIM - Genetic disorder catalog
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What other names do people use for the TSHB gene or gene products?
- thyrotropin beta chain precursor
- thyrotropin beta subunit
- TSH-BETA
- TSHB_HUMAN
Where can I find general information about genes?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding TSHB?
The resources on this site should not be used as a substitute for
professional medical care or advice. Users seeking information about
a personal genetic disease, syndrome, or condition should consult with a qualified
healthcare professional.
See How can I find a genetics professional in my area? in the Handbook.