McCune-Albright-Braytsev syndrome: literature review and clinical case

Abstract

The paper presents the results of literature review on McCune-Albright-Braytsev syndrome and describes the clinical case of this syndrome. McCune-Albright-Braytsev syndrome is a genetically determined disease, usually chara­cterized by a triad of symptoms: the presence of specific cafe-au-lait spots, fibrous dysplasia of the bones and various endocrinopathies, the most frequent of which is premature sexual development. The incidence of this disease in the world varies from 1 case per 100,000 to 1 case per million in the general population. McCune-Albright-Braytsev syndrome is caused by a mutation in GNAS1 gene. This gene encodes the alpha subunit of guanosine triphosphate bin­ding protein (G protein), which stimulates the formation of cyclic adenosine monophosphate (cAMP) that, among other things, regulates the work of many endocrine glands in the body. The mutant protein constantly activates adenylate cyclase, the intracellular level of cAMP increases, which leads to spontaneous “inclusion” of hormone secretion. GNAS1 is on the long shoulder of chromosome 20. This cell mutation occurs in the early stages of embryogenesis. The described clinical case is of unquestionable interest in terms of somewhat delayed diagnosis of the syndrome, although pathological fractures are the classic signs of the disease. The success of the treatment of this disease directly depends on the early diagnosis and timely referral of the child to the appropriate endocrinological institution.