Investigators have found that intravenous infusion of a CRISPR-Cas9 based gene therapy decreases serum transthyretin (TTR) protein in patients with hereditary TTR amyloidosis (ATTR).
Wildtype TTR protein is expressed primarily by the liver to carry thyroid hormone and vitamin A. However, mutations in TTR lead to destabilization and misfolding that precipitates accumulation in the myocardium, spine, peripheral nerves, and other organs.