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McCune–Albright syndrome, or simply Albright syndrome, described in 1937 by Donovan James McCune and Fuller Albright, is a genetic disorder of bones, skin pigmentation and hormonal problems along with premature puberty. ==Signs and symptoms== McCune–Albright syndrome is suspected when two of the three following features are present: * Autonomous endocrine hormone excess, such as in precocious puberty * Polyostotic fibrous dysplasia * Unilateral café au lait spots Within the syndrome there are bone fractures and deformity of the legs, arms and skull, different pigment patches on the skin, and early puberty with increased rate of growth. Approximately 20-30% of fibrous dysplasias are polyostotic, which means fibrous dysplasia and sclerotic bone are present in multiple sites; two thirds of patients are polyostotic before the age of ten. The disease frequently involves the skull and facial bones, pelvis, spine and shoulder girdle. The sites of involvement are the femur (91%), tibia (81%), pelvis (78%), ribs, skull and facial bones (50%), upper extremities, lumbar spine, clavicle, and cervical spine, in decreasing order of frequency. The craniofacial pattern of the disease occurs in 50% of patients with the polyostotic form of fibrous dysplasia. Increased production of hormones by glands regulated by the G protein system is due to a mutation in the gene causing continuous activation of stimulatory G protein. This results in the so-called "autonomous production" of hormones, including thyroid hormone, cortisol, estrogen and growth hormone. Therefore, hyperthyroidism, Cushing syndrome, precocious puberty in women with premature thelarche (breast growth), premature menarche (beginning of menstrual function), increased speed of growth and growth hormone excess can ensue. Increased serum estrogen concentrations correlate with large ovarian cysts. Ovarian cysts appear and disappear with changing estrogen concentrations, causing menstrual bleeding when estrogen decreases. McCune–Albright syndrome has different levels of severity. For example, one child with McCune–Albright syndrome may be entirely healthy, with no outward evidence of bone or endocrine problems, enter puberty at close to the normal age, and have no unusual skin pigmentation. Diagnosis may be made only after decades. In other cases, children are diagnosed in early infancy, show obvious bone disease, and obvious increased endocrine secretions from several glands. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「McCune–Albright syndrome」の詳細全文を読む スポンサード リンク
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