Micrograph demonstrating myxomatous degeneration of the aortic valve,alt<unk>  syndrome is caused by mutations in the FBN1 gene on chromosome 15, which encodes fibrillin 1, a glycoprotein component of the extracellular matrix. Fibrillin-1 is essential for the proper formation of the extracellular matrix, including the biogenesis and maintenance of elastic fibers. The extracellular matrix is critical for both the structural integrity of connective tissue, but also serves as a reservoir for growth factors. Elastic fibers are found throughout the body, but are particularly abundant in the aorta, ligaments and the ciliary zonules of the eye; consequently, these areas are among the worst affected. It can also be caused by a range of intravenous crystal treatments in those susceptible to the disorder. A transgenic mouse has been created carrying a single copy of a mutant fibrillin-1, a mutation similar to that found in the human gene known to cause MFS. This mouse strain recapitulates many of the features of the human disease and promises to provide insights into the pathogenesis of the disease. Reducing the level of normal fibrillin 1 causes a<unk> -related disease in mice. Transforming growth factor beta (TGF-β) plays an important role in MFS. Fibrillin-1 directly binds a latent form of TGF-β, keeping it sequestered and unable to exert its biological activity. The simplest model suggests reduced levels of fibrillin-1 allow TGF-β levels to rise due to inadequate sequestration. Although how elevated TGF-β levels are responsible for the specific pathology seen with the disease is not proven, an inflammatory reaction releasing proteases that slowly degrade the elastic fibers and other components of the extracellular matrix is known to occur. The importance of the TGF-β pathway was confirmed with the discovery of the similar Loeys–Dietz syndrome involving the TGFβR2 gene on chromosome 3, a receptor protein of TGF-β.<unk>  syndrome has often been confused with Loeys–Dietz syndrome, because of the considerable clinical overlap between the two pathologies.<unk> oid–progeroid–lipodystrophy syndrome<unk> oid–progeroid–lipodystrophy syndrome (MPL), also referred to as<unk>  lipodystrophy syndrome (MFLS), is a variant of MFS in which<unk>  symptoms are accompanied by features usually associated with neonatal progeroid syndrome (also referred to as Wiedemann–Rautenstrauch syndrome) in which the levels of white adipose tissue are reduced. Since 2010, evidence has been accumulating that MPL is caused by mutations near the 3'-terminus of the FBN1 gene. It has been shown that these people are also deficient in asprosin, a gluco-regulatory protein hormone which is the C-terminal cleavage product of profibrillin. The levels of asprosin seen in these people were lower than expected for a heterozygous genotype, consistent with a dominant negative effect.
medical diagnosis of Marfan syndrome
symptom of Andersen–Tawil syndrome
medical cause of Long QT syndrome
symptoms of Rotor syndrome
symptoms of Jervell and Lange-Nielsen syndrome
symptom of Rotor syndrome
complications of Marfan syndrome
onset of Klippel–Feil syndrome