Fibrillin-1 (FBN1)

Fibrillin-1 is a large, cysteine-rich, calcium-binding glycoprotein encoded by the FBN1 gene on chromosome 15q15-21.1, and is the major structural component of 10–12 nm microfibrils in the extracellular matrix of elastic and non-elastic connective tissues[2][6][4]. It is essential for microfibril assembly, tissue elasticity, and regulation of transforming growth factor-beta (TGF-β) signaling, thus playing a pivotal role in the structure and function of blood vessels, skin, ligaments, and other tissues[2][4]. Defects or mutations in FBN1 can result in Marfan syndrome, Weill-Marchesani syndrome, and a spectrum of other connective tissue disorders[3][6]. Fibrillin-1 is not itself a direct therapeutic drug target, but its loss or mutation causes disease through effects on tissue mechanics and dysregulated signaling pathways[2][3]. "Fibrillin-1 expression" is not a standard therapeutic target name, but refers to the expression level of fibrillin-1; the actual molecule of interest is fibrillin-1 (FBN1). No current drugs directly target fibrillin-1; intervention is usually symptomatic or targets downstream effects (e.g., TGF-β pathway modulation in Marfan syndrome). FBN1 can be used as a biomarker for diagnosis and genetic testing of Marfan syndrome and related disorders[4]. Expression or structural defects in FBN1, not pharmacologic targeting, are clinically significant.

Other names

FBN1Fibrillin IEctopia lentis syndrome protein

Null (no direct pharmacologic targeting described; mechanism in disease is through structural and signaling dysregulation)