TTN

About TTN

TTN on chromosome 2q31.2 encodes titin, the largest known human protein, which spans half a sarcomere from the Z disc to the M line in heart and skeletal muscle. It acts as a molecular spring that provides passive elasticity, helps assemble and stabilize the sarcomere, and participates in signaling. The gene contains hundreds of exons, and alternative splicing produces isoforms of differing stiffness in different muscles. Truncating variants in TTN are the most common known genetic cause of dilated cardiomyopathy, found in a substantial minority of familial cases, and they are also associated with peripartum cardiomyopathy and alcohol associated cardiomyopathy. Other TTN variants cause a range of skeletal muscle disorders, including tibial muscular dystrophy, first described in Finland. Because truncating TTN variants are also found in some healthy people, their interpretation depends on where in the gene they lie.