McCune-Albright syndrome is a rare clinical syndrome of congenital endocrine disorders with patchy skin pigmentation and multiple cystic fibrous dysplasia, which is an ornithine nucleic acid binding protein disease (G protein disease). The endocrine dysfunction can be manifested as precocious puberty, hyperthyroidism, Cushing’s syndrome, prolactinoma, hypersecretion of growth hormone, cortisolism, anti-vitamin D hypophosphatemia and enlarged parathyroid glands, with precocious puberty being the most common. The disease is sporadic and is twice as common in females as in males. Etiology The genetic basis of the disease is a mutation in the guanine nucleotide-binding protein (G protein) a subunit (Gsa) gene during embryogenesis. The common mutation is an Arg 201 His or Arg 201Cys missense point mutation in exon 8 of the gene encoding the Gsa subunit located on the long arm of chromosome 20. The mutation causes a marked increase in the level of cyclized adenosine 3,5-2 phosphate in the intracellular matrix at the site of the lesion, resulting in spontaneous activation of CAMP-dependent receptors (e.g., ACTH, TSH, FSH, LH receptors, etc.) in The process of autocrine hormone overproduction or hormone resistance occurs in endocrine gland tissues. Only some of the somatic cells that are mutated will survive, otherwise abortion will occur. McCune-Albright syndrome is characterized by the following triad of clinical manifestations: (1) autonomic hyperfunction due to hyperplasia or adenoma of one or more endocrine glands. The most common is the development of autonomous functional follicular cysts in the ovaries, resulting in sex hormone activity without gonadotropic activity and ovulation, leading to non-GnRH-dependent precocious puberty, which is characterized by early development of secondary sexual characteristics, early menstruation, changes in sexual characteristics and intermittent vaginal bleeding, and absence of ovulation. Early bone marrow maturation. Increased blood estrogen levels and low gonadotropin levels, fluctuations in estrogen levels often coincide with autonomous changes in follicular function, and low LH response to GnRH stimulation tests. However, prolonged hypergonadotropic state can induce true precocious puberty. Other endocrine gland lesions may also cause hyperthyroidism, cortisolism, gigantism, acromegaly, or hyperprolactinemia. (2) Multiple heterogeneous proliferation of bone fibers. It mostly involves craniofacial bones and long bones, with a heterogeneous asymmetric distribution and facial asymmetry, often manifesting as local pain and skeletal deformity, prone to pathological fractures in young age and decreasing in adulthood. Sometimes skeletal proliferation can cause local compression symptoms, such as cranial lesions compressing nearby nerves causing blindness and deafness, and compressing the pituitary gland causing endocrine dysfunction. (iii) Irregularly bordered cutaneous café-au-lait pigmentation. They are not always present at birth and tend to occur ipsilateral to the bone lesion, rarely beyond the midline. The severity of the clinical symptoms is related to the early onset of the mutation during the embryonic period. The early onset of the mutation results in a wide range of lesions and a typical triad of symptoms. If the mutation is late, the lesion may be small or even isolated. Differential diagnosis McCune-Albright syndrome has a typical triad of the above-mentioned symptoms and is easily diagnosed. However, if the lesion is atypical, it should be differentiated from central precocious puberty, hyperparathyroidism, hyperthyroidism, ovarian tumors, neurocutaneous syndrome, and Paget’s disease. Treatment and prognosis The treatment of McCune-Albright syndrome is mainly symptomatic and there is no effective cure. Precocious puberty can cause psychological burden to the child and parents, and may lead to early closure of the bone marrow and affect the final height. The control of other endocrine gland hyperfunction directly affects the survival status of the affected children. Abnormal proliferation of bone fibers can lead to skeletal deformities, functional abnormalities or fractures. Treatment mainly includes: ①Treatment of endocrine gland hyperfunction: In the past, aromatase inhibitors such as testosterone and high-efficiency progesterone (i.e. progesterone) were mainly used. These drugs can also occur after 3 years of application. In addition, Danazol, Saxilone acetate, high-dose ketoconazole, etc. have been used clinically, but the side effects are too great and less used at present. In China, some results have been achieved by treating children with the antineoplastic drug tamoxifen, which competes with estradiol to bind estrogen receptors, thus causing estrogen levels to decrease. It deserves further exploration. The third-generation aromatase inhibitor letrozole has been shown to be effective in the treatment of peripheral precocious puberty in a small sample of female children with MAS, mainly in terms of slowed growth, slower bone age progression, and cessation or reduction in the frequency of vaginal bleeding. It is conducive to improving the final height and has fewer side effects. (2) Bone abnormalities: bisphosphonates can be tried to inhibit bone resorption; bone diseases can be treated with scraping, fracture management, and deformity prevention. Special complications caused by bone disease, such as narrowing of the optic nerve foramen due to fibrosis of the skull base or orbit, leading to visual impairment and even blindness, can be treated surgically.