PT  - JOURNAL ARTICLE
AU  - Wang, Lili
AU  - Yang, Yang
AU  - Breton, Camilo
AU  - Bell, Peter
AU  - Li, Mingyao
AU  - Zhang, Jia
AU  - Che, Yan
AU  - Saveliev, Alexei
AU  - He, Zhenning
AU  - White, John
AU  - Latshaw, Caitlin
AU  - Xu, Chenyu
AU  - McMenamin, Deirdre
AU  - Yu, Hongwei
AU  - Morizono, Hiroki
AU  - Batshaw, Mark L.
AU  - Wilson, James M.
TI  - A mutation-independent CRISPR-Cas9–mediated gene targeting approach to treat a murine model of ornithine transcarbamylase deficiency
AID  - 10.1126/sciadv.aax5701
DP  - 2020 Feb 01
TA  - Science Advances
PG  - eaax5701
VI  - 6
IP  - 7
4099  - http://advances.sciencemag.org/content/6/7/eaax5701.short
4100  - http://advances.sciencemag.org/content/6/7/eaax5701.full
SO  - Sci Adv2020 Feb 01; 6
AB  - Ornithine transcarbamylase (OTC) deficiency is an X-linked urea cycle disorder associated with high mortality. Although a promising treatment for late-onset OTC deficiency, adeno-associated virus (AAV) neonatal gene therapy would only provide short-term therapeutic effects as the non-integrated genome gets lost during hepatocyte proliferation. CRISPR-Cas9-mediated homology-directed repair can correct a G-to-A mutation in 10% of OTC alleles in the livers of newborn OTC spfash mice. However, an editing vector able to correct one mutation would not be applicable for patients carrying different OTC mutations, plus expression would not be fast enough to treat a hyperammonemia crisis. Here, we describe a dual-AAV vector system that accomplishes rapid short-term expression from a non-integrated minigene and long-term expression from the site-specific integration of this minigene without any selective growth advantage for OTC-positive cells in newborns. This CRISPR-Cas9 gene-targeting approach may be applicable to all patients with OTC deficiency, irrespective of mutation and/or clinical state.