Novel OBSCN variants associated with a risk to exercise-intolerance and rhabdomyolysis.

Obscurin, encoded by the OBSCN gene, is a muscle protein consisting of three main splice isoforms, obscurin-A, obscurin-B, and obscurin kinase-only protein (also known as KIAA1639 or Obsc-kin). Obscurin is located at the M-band and Z-disks and interacts with titin and myomesin. It plays an important role in the stability and maintenance of the A- and M-bands and the subsarcolemmal organization of the microtubule network.