Fig. 4. AAV9-Cas9 silencing of the pathogenic variant R403Q and cardiac function in R403Q-129SvEv mice.

a, Schematic of the genomic sequence surrounding the HCM R403Q pathogenic variant, showing the pathogenic variant R403Q (numbered according to the human MYH7 amino acid residues) and flanking amino acid residues (N, amino terminus; C, carboxyl terminus). The S. aureus Cas9 nuclease protospacer (green line), PAM site (purple line) and double-stranded cleavage position of the nuclease (dotted orange line) are shown. b, The percent of inactivation of the R403Q allele after 1 × 10¹³ vg kg⁻¹ of AAV9-Tnnt2-S. aureus-Cas9 (designated AAV9-Cas9) was assessed by sequencing Myh6 cDNA, amplified from RNA extracted from each cardiac chamber of surviving R403Q-129SvEv mice (n = 4 males) at 33 weeks. The percentage of inactivation of the pathogenic variant R403Q was calculated as: (1 − (total number of R403Q reads, divided by total number of WT reads)) multiplied by 100. c, Longitudinal echocardiographic measurements (defined in Fig. 2) of the LVPW (left panel), LVPW/LVDd ratio (middle panel) and %FS (right panels) in WT R403Q-129SvEv (n = 4 males; black line), untreated R403Q-129SvEv (n = 10 males, red line) and treated (AAV9-Cas9) R403Q-129SvEv (n = 5 males; blue line) mice. Note impaired contractile function (FS <40%) in treated mice. Data are presented as mean values ± s.d., and significance was assessed by two-tailed t-test (Supplementary Information).

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