[7] The 900 kb gene for utrophin is found on the long arm of human chromosome 6.

It was found by screening a peptide containing the C-terminal domain of dystrophin against cDNA libraries.

In normal muscle cells, utrophin is located at the neuromuscular synapse and myotendinous junctions.

In adult humans, utrophin RNA is found ubiquitously, as the name implies, being abundant in the brain, kidney, liver, lung, muscle, spleen and stomach.

Utrophin expression is dramatically increased in patients with Duchenne's muscular dystrophy (and female carriers), both in those muscle fibers lacking dystrophin and in rare, revertant fibers that express dystrophin.