The bone is replaced by abnormal scar-like (fibrous) connective tissue
The human skeleton is living tissue that is constantly changing (remodeling) meaning bone gradually breaks down (bone resorption) and then reforms, part of that is due osteoblasts which are immature bone-forming cells that form new bone and cells that control bone resorption (osteoclasts).
The complex interaction and other factors as well as between osteoclasts and osteoblasts determines how bone reforms.
When there is an increased turnover of osteoblast there seems to be an increase in scar-like (fibrous) connective tissue.
The skin has brown patches called cafe au lait spots (See medick chapter)
The pituitary gland starts releasing its hormone easily causing a range of symptoms.
The pituitary gland is responsible for the following hormones
Growth hormone (GH)
This hormone controls bone and tissue growth and maintains the right balance of muscle and fat tissue.
Thyroid-stimulating hormone (TSH)
This hormone stimulates your thyroid gland to produce key hormones that regulate your metabolism. Shortage of TSH results in an underactive thyroid gland (hypothyroidism)
Luteinizing hormone (LH)
In women, LH regulates estrogen.
Follicle-stimulating hormone (FSH)
Working with LH, FSH helps stimulate egg development and ovulation in women.
Adrenocorticotropic hormone (ACTH)
This hormone stimulates your adrenal glands to produce cortisol and other hormones.
Cortisol helps your body deal with stress and influences many body functions, including blood pressure, heart function and your immune system.
A low level of adrenal hormones caused by pituitary damage is called secondary adrenal insufficiency.
Prolactin
This hormone regulates the development of female breasts, as well as the production of breast milk.
Cause
A genetic change (mutation) in the GNAS1 gene that occurs randomly, for no apparent reason.
The GNAS1 gene is located on the long arm (q) of chromosome 20 (20q13.2) Chromosomes, which are present in the nucleus of human cells, carry the genetic information for each individual
The GNAS1 gene creates (encodes) a subunit of a protein known as a G-protein. In MAS, a gain-of-function mutation in the GNAS1 gene results in continuous activation of this G-protein. In turn, there is an overproduction of a molecule known as cyclic adenosine monophosphate (cAMP), which is involved in various chemical processes of the body.
Hypophosphatemia (because the fibrous scar tissue produces produces a protein known as fibroblast growth factor 23 (FGF23) and this affects the kidney ability to reabsorb the phosphate)
A rare disorder characterized by displacement of normal bone tissue with areas of fibrous growth (fibrous dysplasia) within the upper and/or lower jaw bones (maxilla and/or mandible) on both sides of the face (bilateral).
This causes abnormal expansion of the jaw bones, unusual chubbiness and swelling of the face, and, in severe cases, “upturning” of the eyes. In some cases, fibrous dysplasia may also occur in other bones of the body, particularly the ribs.
Some affected individuals may also exhibit other abnormalities such as multiple, patchy areas of dark pigmentation (cafe-au-lait spots) and/or several warty birthmarks (nevi) on the skin. Symptoms usually become apparent in the third or fourth year of life. Cherubism is thought to be inherited as an autosomal dominant genetic trait with variable expressivity and penetrance. Whereas 100% of affected males with a defective gene for cherubism will exhibit the characteristics typically associated with the disorder (high penetrance), only 50 to 75% of females with the disease gene demonstrate symptoms of the disease (reduced penetrance). Mutations in the SH3BP2 gene are associated with approximately 80% of individuals with cherubism.
Please copy and paste any key words from the title: McCune Albright syndrome in the following respective 'Medtick References and/or Sources' to find out more about the disease (this also may include diagnosis tests and generic medical treatments).
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